Jack has never been a very religious person. He did spend eight months in a Sirusan Neo-Orthodox revival cult when he was sixteen, granted, but that was less about faith than it was about the ritual sex. (Sirusan Neo-Orthodoxy had a revival when everyone was sixteen; the cycle was driven by each new generation's sudden discovery of the wonders of temple prostitution. And eight months was fairly typical: just long enough for the hormones to fade and the worshipers to realize that there were easier ways to get laid than following the arbitrary and illogical edicts of a belief system as inherently contradictory as Neo-Orthodoxy. It had been widely accepted as the adolescent experiment of choice ever since a nasty schism over alloys broke the Church of the Tin Vagabond in 4792.) So he doesn't have anything against religion, and he actually remembers his brief fling with spirituality quite fondly, but he never received anything that could be described as formal religious education.
Jack does not count his academy crash course on Ancient Religions 101: How Not to Be Sainted, Scourged, or Sacrificed as formal religious education.
Still, taking the slow road through the 20th century has made it hard to miss the high points of Christianity and he's learned enough to recognize that recent events, Abaddon and the Rift and the whole unholy mess, are all terribly biblical. Denounced and betrayed by his disciples, check. Sacrificed himself to save humanity, check. Dead for three days before coming back to life, check. It's almost enough to make him wonder if he didn't slip a couple thousand years farther back while he wasn't paying attention. It's certainly enough for him to start making plans for when the team gets back with the coffee; maybe telling them that they can address him as Jesus from now on will knock that half-awed look out of their eyes.
But Jesus jokes are going to have to wait. He's forgotten the most important part; the dinner and drinks come before the death and the resurrection, not after. The last scene of the passion play is the ascension into heaven: leaving the Earth behind and finally going home. The right hand of the Lord is calling.