A couple of months ago, someone asked me to explain why I believe God exists.
I start with this premise: For anything to exist at all, something has had to have always existed. If at some point in the past, nothing existed, nothing would exist today. Nothing produces nothing. Nothing cannot produce something.
Since things exist, something must be self-existent. Something must have existed forever.
At this point, we have two options:
1. The material universe has always existed.
2. Something beyond the material universe has always existed and is responsible for the creation of the material universe.
Historically, some have held to the eternality of the material universe. However, evidence suggests that the universe had a beginning. Based on current data, scientists theorize that everything began with a "big bang." The specifics of scientific theories may or may not be correct, but all evidence points to a beginning for the universe nonetheless.
Since the first option has been discredited as non-viable, the second option would stand alone as a reasonable explanation for the existence of the universe. Something beyond the material universe has always existed and is responsible for the creation of the material universe. We would refer to this Creator as God.
"In the beginning God created the heavens and the earth" (Genesis 1:1).