I never heard him say that "cliff diving is going to make Jesus happy or make others believe in him". What he said was "I chose to do it so it would open up doors so I could witness my faith in Christianity." But people who are intolerant of others' beliefs choose to hear what they want to hear.
POD chooses to grow dreads, get tattooed and rock hard to "witness their faith". Those bodybuilder guys with the MC hammer pants on late-night television choose to rip phonebooks apart to "witness their faith". JP chooses to huck his carcass off cliffs. Machinegun guitars, ripped phone books and big air aren't going to make people believe in Jesus, they give those people an access to talk to people who dig metal, extreme skiing, and... uh... buff guys who rip phone books in half.
Like double-a-ron said, do what ya do.....
For those that don't pretend to know what's best for someone else... here's another one of his big ones. Looks kind of fun to me. http://www.tetongravity.com/cotw/cotw104fast.htm