One argument against the truth of Christianity is that if Christ came to change the world, He clearly failed. History AD is no more moral or loving than history BC.
Indeed, the very institutions of Christianity succumbed almost immediately to the very sins of pride and power that were the target of Christ’s preaching.
Christ opposed the legalistic tyranny of the Law (Torah, etc.) as enforced by men. His church, as soon as Constantine legalized and empowered it, began using the state and law to dominate society and impose conformity. Apostasy, for instance, was treated by the church in a manner no better than that of modern Islam. Only the anti-Christian Enlightenment put an end to Christian inquisition and persecution.
So if Jesus’ life, death and resurrection were the unique divine revelation and intervention that Christians believe them to be, why isn’t the world morally superior today to it was BC?
One possible answer: The world IS different, and even arguably superior. Men still sin, but now they cannot help but know their sin. Now, one must argue with God to justify one’s sin and hate. BC, no one preached that God is love. No one taught a moral obligation to love your neighbor, and your enemy, and those that hate you.
Once these teachings were loose in the world, then the face of sin was exposed. Of course, the counterpoint is that hypocrisy, lying to ourselves and others about our actions and motives, became a prime commodity.
To read the highest thoughts of the BC mind is to confront a world before hypocrisy. Thucydides, on the Melian dialogue, shows foreign policy discussed with no pretension of any concern for humanity. Plato’s Republic shows Socrates asking the sophist Thrasymachus: “Are the unjust in your opinion good as well as prudent?” Thrasymachus answers “Yes, those who can do injustice perfectly, and are able to subjugate cities and tribes of men to themselves.”
It is difficult to imagine these exchanges taking place AD. There are still bloodthirsty, cold-hearted “realists” ready to embrace genocide or injustice; but they know what they are doing. And one way or another, they must attempt to justify themselves to God.
As I say, a possible answer.