You fail to distinguish between people habitually being good and why they should maintain those habits. Once habits are established, living the Christian manne

You fail to distinguish between people habitually being good and why they should maintain those habits. Once habits are established, living the Christian manner is preferable. But, without a justification for doing so, the habits are not established, and they can be broken at a whim. This is the case with the "moral" atheists. They have grown up in a Christian culture and adopted the Christian moral habits. But, if it is ever in their favor to discard the moral habits, the atheist will do so. For instance, why give up your life for others? There is no justification for this in an atheist worldview, and without it, we would not have firefighters, police, or the military. Instead, we'd just have mercenaries that would just as soon massacre you instead of the enemy, if the enemy pays them more.