Christianity teaches that we should love our enemies, and as much as possible, we should live in peace with all men. Some branches of Islam believe that one should behead their enemies. Again, for this point, which view is correct is irrelevant. Still, for anyone to have a meaningful conversation about which statement (if either) is accurate, one must assume that a proper view does exist. This requires an objective moral standard. So unless objective moral categories of good, evil, right, and wrong exist in reality, our tendency to think in these terms is unexplainable.

Here are questions to ask considering an Objective Moral Standard:
Can human beings construct an objective moral standard independent of God?
Can evolution or creationism explain morality?
Does Truth Exist?

Atheism Fails to explain why we are obligated to fulfill or align our lives with any of these moral values that lead to human flourishing.
The atheistic Worldview is ultimately self-refuting! Harris, as a naturalist (the view that only nature exists), holds to "scientific determinism," which means he believes our thoughts and actions are causally determined by natural forces like physics, chemistry, and the initial conditions of the big bang. Therefore, humans could never freely choose any action, including actions with supposed moral properties. If naturalistic atheism is accurate, we have no logical grounds for objective moral values and no rational grounds of objective duty to align our lives with any personal codes of ethics. By making this move, however, they affirm that there is nothing wrong with Hitler's Holocaust, the molestation of young boys in the Penn State locker room by Jerry Sandusky, or the murderous actions of ISIS.

So here's how it goes then:
1- If God does not exist, objective moral values and duties do not exist.
2- Objective moral values and commitments DO exist.
3- Therefore, God exists.