I completely bailed out when a friend asked me this earlier. He saw me carrying Does God Believe in Atheists, and when he asked, I told him how it proposed that a Christian worldview makes best sense of the world.
"What, you mean creationsim and stuff?" (He's a physisist) - it's amazing how many people focus not on Jesus, but on the relatively impersonal, abstract Genesis of the universe. Whether the world was created in six days or 6 billion years continues to be debated, but I don't think the argument tends to bring people to Jesus.
We got on to talking about purpose vs entropy, at which point he asked why the universe couldn't just be random...
