Why Should We Believe that Christianity is True? Part 4 – the Gospel

  1. Lord, Liar, Lunatic
  2. The Resurrection
  3. God and Revelation
  4. The Gospel


If someone asked you to explain to them the most fundamental reason that you were a Christian, what would you say?

This is part four in a four-part series which provides a few foundational apologetic arguments for the truth of Christianity. In part one, we looked at the Lord, Liar, Lunatic argument that can be formulated from the life of Jesus in the gospels. In part two, we looked at the strength of the historical evidence for the bodily Resurrection of Jesus. In part three, we examined several pieces of evidence for the existence of God drawn from science and philosophy. In this final essay, I’d like to outline what I think is the most powerful argument for Christianity: the gospel itself. The gospel is the central message of Christianity: that in his life, death and Resurrection, Jesus made it possible for us to be forgiven and reconciled to God.

It may strike you as odd to think of ‘the gospel’ as the basis for an apologetic argument. We usually assume that apologetic arguments are meant to remove intellectual obstacles prior to an explanation of the gospel. But can the gospel itself give us an independent reason to think that Christianity is true? I believe that it can. My claim is that the gospel alone presents us with two fundamental truths that all of us must face as human beings: first, we are all moral failures. And second, we all need a savior. Of all the major world religions, only Christianity insists that we are radically morally corrupt and only Christianity insists that what we primarily need is not moral improvement, but rescue. If these claims turn out to be true, then they are strong evidence for the truth of the Christianity, which is unique in its assessment of the human condition. But are they true? Let’s examine both propositions.

Are we really moral failures?

First, the Bible declares that we are all radically corrupted by sin. Sin is not just ‘breaking the rules.’ Sin, at its heart, is our rebellion against our good and loving God, and our rejection of Him as our Lord and Savior. It is not that we are prone to do good but occasionally do evil. It is that we are desperately evil, even in our best moments. Consider a few of the depressing, but candid, assessments of the biblical authors:

“The LORD saw that the wickedness of man was great in the earth, and that every intention of the thoughts of his heart was only evil continually.” – Gen. 6:5

“Against you, you only, have I sinned and done what is evil in your sight, so that you may be justified in your words and blameless in your judgment. Behold, I was brought forth in iniquity, and in sin did my mother conceive me.” – Psalm 51:4-5

“None is righteous, no, not one; no one understands; no one seeks for God. All have turned aside; together they have become worthless; no one does good, not even one.” – Rom. 3:10-12

According to the Bible, our primary problem is not a lack of self-affirmation, a bad environment, or even material poverty. Our primarily problem is our deep, hopeless, irremediable sin.

Many people find the biblical understanding of sin to be very difficult to accept. While they may recognize that they aren’t perfect, they reject the idea that they have some pervasive inclination towards evil that affects every area of their lives. So do we have good reason to think that we are all moral failures radically infected by sin?

To begin answering that question, let’s start not with anyone else’s moral standards, but with the ethical standards that we ourselves had as children. Have we lived up to them? At one point, many of us probably dreamed of working for world peace, of fighting evil and injustice, of righting the world’s wrongs. But as we grew older, our concern for right and wrong was slowly replaced by concern and enthusiasm for personal pleasure, for possessions, for power, for success. What would the innocent five-year-old version of ourselves think about the person we’ve become? Little children will often cry when they see images of people hurt or suffering. We don’t we? How have we become so hardened? We insist that we have merely ‘outgrown our values’ or ‘matured’ or ‘gotten realistic’. But isn’t the depressing truth that we have simply rejected the love and purity and compassion that should have governed our lives?

We could similarly consider the standards we expect of other people. We want to be treated with love, gentleness, respect and charity and are upset when we feel that others have transgressed this standard. But do we fulfill it ourselves? Can we look back at our lives and truly claim that we have lived as we ought to have lived and as we wished other people lived? Can we look at our past, strewn with broken friendships, betrayals, and bitterness and say that we have never been to blame? Even if we consider our actions to have been unimpeachable, do we ever consider our thought life? Is there an ex-girlfriend or ex-boyfriend whose life we have damaged irreparably? Has there never been a schoolmate who in the loneliness of his room has cursed our cruelty or our bullying? If all of our most private thoughts – our sexual urges, our jealousy, our anger, our self-righteousness – were made audible for everyone to hear, would we dare to even leave our house? A moment of serious reflection on our past conduct should cause us to shudder.

But most of us recognize that each person’s personal standards do not define ethical behavior. For instance, Neoatheist author Sam Harris or atheist ethicist Peter Singer would argue that morality requires us to do as much good as possible to as many people as possible every moment of our lives. They do not invoke God to ground this moral duty, but claim that it follows from a purely atheistic view of the universe. Let us assume for a moment that they are correct. Have we lived up to this standard of universal good will? No, we haven’t. Assuming that many of my readers will be Americans, I would point out that our annual income probably places us in the 90th percentile of annual income worldwide. Given that billions of men, women, and children survive on a few dollars a day, how much do we do to alleviate their suffering? Given that our own inner cities are often filled with broken families, impoverished children, and single mothers struggling on welfare, do we joyfully donate our time and talents to share their burdens? When we examine ourselves honestly, we find that we do not want to alleviate the suffering of others if it comes at too high a cost to us. We find in ourselves an overpowering desire to remain ignorant of their condition to protect our own happiness. We would rather entertain ourselves with romantic comedies and action movies than comfort real people in need. We would rather buy hip clothes and electronics than make radical monetary sacrifices. We would rather eat take-out and play video games than visit lonely shut-ins in retirement homes. Why is love so hard and selfishness so easy?

In all of this discussion, I have not invoked religion or God. I have just demonstrated that even by wholly secular standards, we can see that there is something seriously wrong with us. There are depths of our pride, selfishness, pettiness, lust, anger and self-obsession that we hide from ourselves because we cannot bear what they reveal about us. Where our affections should have been focused on God and other people, they have been warped and bent and curved back in on ourselves. This fact explains why no amount of social reform, or education, or even religious coercion can fix us. History is littered with the wreckage of attempts to cure of our problems. Communist regimes meant to bring equality and dignity to the poor, collapsed in totalitarianism, poverty and corruption. The attainment of money and fame has led celebrity after celebrity to isolation, despair and even suicide. The material prosperity of the American dream has done nothing to fill our inner emptiness. So we numb ourselves with alcohol, drugs, sex, and entertainment to hide ourselves from the excruciating reality. When we take an honest look at our own hearts, the misery we have inflicted on ourselves and others, and the state of our world, the Christian explanation becomes not only plausible but unavoidable: something is deeply, radically, irremediably wrong with us.

Do we really need a savior?

But second, Christianity is unique in its identification of what we most need as human beings. Other worldviews and religions offer many different explanations of our fundamental problem and just as many solutions. Secular philosophies say that we can solve our problems through better education, through better government, through income redistribution, through a return to traditional values, through social activism, through therapy. Other religions say that we can solve our problems through good deeds, through morality, through obedience to God’s law, through prayers, through meditation, through rituals, through ascetic practices. But in spite of the vast differences, all of these prescriptions have one thing in common: they all assume that we can fix ourselves. Christianity alone claims that what we need most is a Savior, a rescuer, someone who will do for us what we cannot do for ourselves. Just as the biblical authors declare our desperate moral guilt, they also declare the gracious forgiveness that God has provided:

“there is no distinction: for all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus” – Rom. 3:23-25

“by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast.” – Eph. 2:8-9

“let the one who is thirsty come; let the one who desires take the water of life without price.” – Rev. 22:17

So do we have objective reasons to think that we need a rescue that comes to us freely and entirely unmerited?

I believe that we do. Almost all other systems of thought, whether secular or religious, are based on the premise that we can atone for our moral failures. In other words, if we accumulate enough moral credit, we can offset our moral liabilities. But any reflection on the actual nature of moral failure shows that such reasoning is deeply erroneous. To make the situation as clear as possible, consider a serious offense, like the rape and murder of a young woman. Does anyone really believe that the rapist and murderer can offset his offense by devoting his life to charity? Think of the dead girl, whose life ended in agony, or the weeping parents remembering the child they loved and cherished. What we intuitively recognize is that the only acceptable response from the murderer is the acknowledgment of his guilt and a recognition that nothing he can do could make up for his crime. But if this reasoning applies even to human notions of justice and forgiveness, how much more so would it apply to forgiveness and reconciliation with a morally perfect God? If anyone at all is going to be saved, it must be on the basis of God’s initiative, not on the basis of our good deeds or merit. And that is exactly why the cross of Jesus offers us what no other religion does: a perfect atonement for our sins not achieved by us, but given to us as a free gift. When we see how indelible our moral failures are, we realize that a wholly gracious reconciliation is the only possible solution.

The necessity of grace is also seen in the inadequacy of our attempts at reformation. For example, in reading the previous section, we may have become convicted about our level of financial giving, our involvement with the poor, or our sexual purity and may have resolved to give more or try harder. Yet it is more than likely that, within a few days or a few weeks, all our resolutions will have faded beneath the far greater desire for our own pleasure and comfort. Even more troubling is the realization that our very attempts to live a morally exemplary life are often tainted and sustained by pride. The more successful we are in living up to our moral standards, the more we tend to look down on others whom we regard as moral failures. Whether these others are ‘moral degenerates’ who fail to live up to our standards of religious devotion and sexual purity or ‘hate-filled bigots’ who fail to live up to our standards of tolerance and acceptance, in either case we are exalting ourselves and our own performance. Pride is the rock on which the hopes of the self-achieving moralist are perennially dashed. The only cure for pride is not a more resolute attempt at humility -which is itself simply an expression of our pride- but grace. Grace alone can save us from our pride because grace alone leaves no room for boasting. Only if salvation is an entirely free gift and not something that we achieve can we be set free from the insufficiency of our own efforts and the deadly burden of our own pride.

In summary, my claim is that Christianity is unique in its presentation of two fundamental truths about each of us: we are all moral failures and we all need savior. On the one hand, Christianity has what is perhaps the most radically pessimistic view of mankind of any religion or worldview. We are fallen and hopelessly corrupt. The tragedies we see across the world, throughout history and in our own lives are not aberrations, but symptoms of the evil that lives in all of our hearts. On the other hand, Christianity has a radically optimistic view of God’s grace. Although we are all equally fallen, we are all equally redeemable. If salvation were based on our goodness, our effort, or our ability, then there would be a scale of redemption: some people would be more deserving of salvation than others. But if salvation is based not on our merit, but only on God’s mercy, then no one is outside of its scope and no one can boast in his or her own goodness.

These two doctrines, which lie at the very heart of Christianity, have incredible explanatory power. They explain why we see such misery in the world today. They explain why even the best of us are stained with evil. They explain why many of us have an insatiable longing for reconciliation and acceptance that we seek to fill with money, careers, or human relationships. They explain why our moral striving cannot cleanse us. Speaking personally, Christianity is the only religion or worldview or philosophy that correctly identifies the disease I know I have and the cure I know I need.

Practical suggestions

First, don’t be discouraged if this final argument is met with far more resistance than the other three I’ve discussed in previous posts. One of the main barriers between us and God is our refusal to recognize our own sinfulness. Ultimately, it takes the work of the Holy Spirit to truly convince us of our need for a Savior. In this regard, Scripture will be one of our most powerful tools. Suggest that people read through the Sermon on the Mount in Matthew 5-8 or Jesus’ teaching in the gospel of Luke. Let God use the Bible to demonstrate how far short we fall of what He requires and to point us towards the forgiveness He offers.

Second, we need to be gently shown that the only alternative to humble acknowledgment of our sin is self-righteousness. One of the reasons that prostitutes and tax collectors flocked to Jesus was that they knew they were failures. They knew they needed forgiveness and transformation. On the other hand, the moral, religious people rejected Jesus because they refused to admit that they were just as helpless and corrupt as those they despised. In the same way, our view of our own sin will lead us into one of only two postures towards those we consider the ‘bad people’, whether they are greedy CEOs or sexually immoral drug addicts. Either we can say: “Thank God, I am not like those people; I am one of the good people” or we can say “The same sin that lives in their hearts lives in mine. I am no different than anyone else. God have mercy on me, a sinner.”

Third, it is extremely important to use first-person pronouns when talking about human sinfulness. The biblical claim is not that “they” are all sinners who need a Savior, but that “we” are all sinners who need a Savior. The entire message of the gospel will be undermined if it is presented in a way that exalts our own righteousness and denigrates the other person. A tone of superiority and arrogance not only puts people on the defensive but misrepresents the gospel of grace.

Finally, although this essay presents the ‘argument from the gospel’ as an objective case for the plausibility of the Christian worldview, it needs to also be the existential, personal reality on which we build our faith. I cannot stress this last point enough. At the center of view of the world needs to be the personal, existential recognition that we are great sinners in need of a great Savior. It is not enough to give intellectual assent to these propositions without ever internalizing them. It is possible to acknowledge that man is hopelessly sinful without confessing that you are a hopeless sinner. It is possible to affirm that Jesus is the Savior, without trusting in Jesus as your Savior. These matters are so important because they distinguish a dead faith from a living one. I have spoken with numerous ex-Christians who insisted that they had truly believed, listing their spiritual accomplishments, gifts, piety, and zeal as evidence of their faith. But what was always lacking from their own descriptions was a statement to the effect that they realized that they were a sinner who needed a Savior. What is more, they seemed wholly unaware that such a realization is the very core of Christianity.

In these four posts, I have provided what I think are many compelling intellectual reasons to believe that Christianity is true. But as important as these arguments are, they should never displace the gospel itself. The call of the gospel is to ‘repent and believe the good news,’ to recognize and turn away from our rebellion against God and to believe the good news that God has provided a Savior. The gospel lies at the center of the Christian faith and it needs to be at the very center of our lives as well.

Previous essay: God and Revelation.