Basics:
This discussion will NOT have a final yes or no. The answer is really in your faith.
This is not for bashing Christians, athesists, or for talking about the Crusades or "how all wars are about religion". Or how everyone that doesn't believe is going to hell.
This is only a discussion for scientific observations both for and against the notion of God existing.
Be prepared to back up statements with facts/observations.

The $64,000 question: Does God exist?

Specific topics (feel free to add more):
Complexity of the human brain
Size/expansion of the universe
Space/Time
Decay into chaos vs creation of order
Physically measurable complexities