Many arguments for the existence of God lack the warrant authorizing you to proceed from the premises to the conclusion that God exists. Take the Cosmological Argument, for example. You can assume that the premises are true (although this is frequently disputed, let's assume truth, for brevity's sake). You can then conclude that a First Cause exists.
How an individual maps that First Cause to God is an entirely separate exercise that the assumption of a First Cause doesn't undertake at all.
You see this pattern over and over again - the leap of logic from First Cause (or a Designer, or a Greatest Possible Being, etc.) to the desired conclusion that "therefore God exists".
You and I see this pattern over and over.
Don't be afraid to point it out!