If Christianity were true, you'd expect to be able to find people who would tell of changed lives, of a relationship with God, of having a sure hope for eternity. And you can. But that's not the only argument being made here! You can find somebody who will stick up for almost any falsehood, but delve into the matter, and you are likely to discover the falsehood. What we have here is different - these are people whose lives really have been changed by a relationship with the living God, and were you to get to know them, you'd find it to be true.
But this little sampling of God at work in the lives of individuals isn't all there is - you don't have to get to know these followers of Jesus Christ! Perhaps you already know someone who is a serious and committed follower of Jesus Christ - if not, you likely know where you could find such a person. Here's the challenge: Ask them to tell their story. What has God done in their lives? The evidence is overwhelming if you will take time to consider it honestly.