It is unfortunate that the debate over the existence of God is so dividing. People too readily dismiss either side’s argument. Three questions:
Question 1: Can we separate arguments for religion from arguments for God?
When confronted with typical arguments for God’s existence, the instinctive reaction of a skeptic is to assume the arguer as an agenda. Nine times out of ten, this is the case. However, it might be a huge mistake to assume that it is impossible to only believe in God if you accept religious beliefs as well. The methodology which leads one to religion is faith. All skeptical people should reject this methodology (for good reasons, not just dismissively). The methodology which has led many people to believe in the existence of a “prime mover” or “uncaused cause” is reason, and it is frankly disingenuous, or uninformed, to claim otherwise.
Question 2: Does the concept of God make sense?
This is a common objection to the existence of God. Atheists claim that a god can not exist because the definition implies a contradiction. Others use Occam’s razor and argue that by positing God, you simply add an additional, unnecessary being to your worldview, so there is no reason to bother believing he exists (same reasoning applies to the existence of Zeus, leprechauns, etc.).
If the concept itself doesn’t make sense, or implies a contradiction, I side with the atheists.
Question 3: Does the concept of no-God make sense?
The universe has either an infinite timeline stretching backward, or it does not have an infinite timeline stretching backward. If it does, it follows that there is no ultimate cause to the universe; event Z was caused by event Y which was caused by event X, ad infinitum. If the universe does not have an infinite timeline, by definition the universe would come from nothing.
If atheism, it is either the case that something came from nothing, or there is an infinite regress of events. Theists ask, “Do either of these make sense? If not, what must be the alternative?” (Update: to see this argument fleshed out, go here)