Unbeliever: If there has to be a "god" as the necessary starting point, why does it have to be your god?
Christian: Because there are no other gods.
U: How do you know that?
C: Because God tells us: "For all the gods of the nations are idols, but the Lord made the Heavens" Psalm 96:5
U: What about the gods of the other religions?
C: They don't exist.
U: But other people believe that those other gods exist.
C: I would argue that they don't, as Scripture teaches us that they are "suppressing the truth in unrighteousness."
U: How can you know with any certainty that out of all the world's "Holy Scriptures", only the Scripture of your religion is God's Word?
C: Because if it's not, I would be among the BILLIONS of people wasting their lives following a God that doesn't exist!