Dave Bish has some good advice here.
And here's a recent foray I made into the atheosphere. That's not an invitation for you to join that particular discussion. The thread is dead and I'd ask you not to reawaken it. Join another more recent discussion if you feel like you've got a day or two handy! :)
One thing that re-occurred to me is that "law-gospel" is very handy to keep in mind. In the context where they demand "evidence" for Jesus (and insist on the kind of evidence they're prepared to accept):
LAW: Jesus is the Truth. To take Him seriously you either begin again with Him or you reject Him. What you don’t do is treat Him as a possible player in amongst a cast of other, more certain, truths. If you did so, you would not be treating Him as He is. Therefore you would not be seeking Him.
Put it another way: He is not in the dock, the “evidence” does not stand over Him, and you are not the prosecutor.
That's the law. It flattens us and gives us no grounds for hope in ourselves. But here comes the gospel...
GOSPEL: There is good news! The Truth has sought us. He has come into the world explaining Himself. He became flesh, was witnessed, was handled, was even dissected on full view of the world. The word written, the Bible, will show you Him at full strength. This is far more than a scrap of evidence. This is far more than Him showing up in a laboratory. He hasn't just submitted Himself to experimental conditions, the Truth has given His very Self to us.
The cross stands between law and gospel. It insists that: Here is the living God! This is where to look and nowhere else. Jews look for signs, Greeks look for wisdom, we lay a stumbling block in their way - the cross. That is law. But if, by faith, the stumbling block becomes the Rock on which they build, suddenly the cross is complete gospel. There is good news: the Truth is given to us utterly - far more than we ever demanded as naturalists.
What kind of responses does this get?
Well one person on the thread quoted from me and then responded:
[I had said] If you start with Jesus (and there’s no way to take Him seriously unless you do) then *He* is the Truth.
[He responded] That’s probably your problem then. No-one here takes him seriously.
If you ask me, our role is presenting Christ such that people see they are accepting or rejecting Jesus and not just a world-view. We must never give the impression that the evidence is only "very good" or that Jesus is merely "the most logical option". If we believe that a person's fundamental issue is their personal orientation towards Christ Himself then that's got to be the pivot on which the conversation turns. We confront people with Christ, it's His rejection or acceptance that is at stake. And that ought to be front and centre.
Lots more to say. But those are just a few thoughts...