Heaven Help Us

Main character has a near death experience and sees "the white light" ---- he's called over and instead counter-negotiates: takes them to task for expecting people to take it all on faith and talks them into some miracles of his choosing (namely, a gorgeous body and some languages, plus the ability to know the one thing that will convince a skeptic) then goes back as "the second coming", but with logic and reason, not blind faith, which sets him at odds with the religious power elite.