I see this misunderstanding a lot. In a recent rant from an atheist, directed at a friend, he claimed that the basic message of Christianity, after you ignore the “witchcraft” and “superstition”, are the moral lessons. Treat others as you want to be treated, “go forth and make life better for all you encounter”, and “leave the planet better than we found it”.
Admirable traits, for sure, but as with many, this person is confusing the result with the cause, while cherry-picking the sections he likes, applying an arbitrary standard. Not only is he making claims not sustainable by atheism, he is also demonstrating his profound ignorance of what Christianity really is. We have discussed the shortcomings of atheist morality many times here and elsewhere, so I won’t dwell on that.
So what should we tell this person to demonstrate what Christianity really is? In short, the Christian belief is described in short as creation, fall, redemption and salvation.
Creation is the ex-nihilo coming into existence of all that can be described as having a cause. This is where Christian belief starts, with the belief that an almighty eternal God made our physical and spiritual universe.
Fall refers to the entry of evil into the world. It has had a profound effect on the world we live in and experience, an effect none of us can escape. We see it every day in evil acts, disease, disasters and tragedies.
Redemption refers to that grace our Creator has freely given us. While God expects us to behave in a certain way, He also knows that it is impossible for humans in their weakened sinful state to behave in that fashion. Transgression of the law requires punishment in any culture, and because God’s expectations is the universal moral law, He also punishes transgressions. But because He loves His creation more than we can describe, He also provides for us not to have to face that punishment, but rather sent a substitute to be punished on our behalf, Jesus Christ. We are redeemed before God by resting in the adequacy of Christ’s death to cover our transgressions.
Salvation is reached when our lives are changed by the belief in Christ’s redemptive act, and when that starts to change our lives so that we may act like our atheist friend thinks all people should.
Of course all humans may act in a moral manner from time to time, due to the fact that we share a common creation and common grace, that grace which transfers to all mankind to protect against anarchy and annihilation. But that behavior is still a result of grace, and not of selfish moral compunction.
Can one then be selective when claiming Christians should behave in a certain manner? Of course not, moral behavior in the Christian context is woven tightly into the Christian ground motive described above, and without it there is no compelling unselfish reason to behave in a certain fashion.
I would advise our non-believing friend to gain a deeper understanding of what Christianity is before he makes flippant statements again.