The very existence of the universe proves it. Philosophers from all times and all places have said that everything that begins has a cause. Scientists say that the universe began with a big bang. "Let there be light."

Even the simplest organism has DNA. DNA is a code for the operation of the organism, production of proteins and other components, and for creating new organisms. This is information. All information is created by an intelligence.

Those two things absolutely prove it to me.