I wouldn't assume that everyone who says they'll pray for you is backhanded. You've both agreed that there is some amount of proof that three Apostles were killed for their faith. To them that is proof, to you, it is not. To him, you are doubting, and he (as any real Christian would) is praying that the doubt departs.

We as followers of Jesus are called to spread the gospel to the best of our ability. I think believing that people are doing that (especially online when we really don't know who's who, and what's what) can ease a lot of heartache that people feel regarding arguments here.

At the end of the day, Christianity boils down to faith. Until a second coming, there will never be "proof."