They aren't there to start a new age of peace, they just want to experience Japan as tourists. If it isn't Jesus stigmata acting up or Buddha glowing the two are just good friends that get into wacky situations as they take in Japanese culture.
The manga sparked a movie and two OVA episodes that came out in Japan a year or so ago. The film caught my attention in one part for a reference to TTDILA's favorite Kamen Rider: Fourze, the space rider, sorry Gaim, fruit-rider.
A few neighborhood brats pester Buddha by trying to hit his dot on his forehead with rubber-bands. This is a weak spot for Buddha and it does give him some pain. One of the brats got a Kamen Rider Fourrze mask as the local festival Buddha and Jesus are attending. The series must have come out when Kamen Rider Fourze was on the scene as the punks idolize him and even refer to his catchphrase of, "It's Space Time" , and do his heroic opening pose.
The second OVA features a strange dream by Buddha where him and Jesus take on the forms from Space Invaders. Buddha is a ship and Jesus a shield. When Buddha cannot die, after he gets resurrected after losing his last life again and again he finally reaches enlightenment in the the game powering him up.
The film and OVAs are unavailable in North America at this time and have no formal distributor in the US.