Answer? One

One. We are all Jesus. We are all the Lightbulb. We are all screwed in by ourselves. (submitted by the Buddha (you) while wearing everything and nothing)
One, if he were to want to screw in a lightbulb. Normally he would just tell the fire flys to congregate in the area of his choice. (submitted by our callipygian loving friend on the bayou "Bubba-the booty man" wearing Just the Fact's Ma'am)
One plus a time machine to take him to the 20th century for a lightbulb. (submitted by the naked "Peter Peter pumpkin eater")
Just one but being Jewish it'll be the cheapest bulb he can find. (submitted by that oddly named goy, "There is no bomb but Nikolai and Micah is his prophet da bomb" wearing a shirt of hair and steel toed sandals.
One. He simply brings the filament from the old one back from the dead. (submitted by Mahatma Kote wearing 100% Cotton.)
One to screw the lightbulb while the other is fucking Mary Magdeline. (obviously submitted without much thought by buster bootyknocker wearing Chanel No. 5)
One. Cause I guess there is only one Jesus. Wait what was the question again? (submitted by Tyrannosauras RUMP who some how squeezed into The Complete Red Leather Thriller Outfit with black fringes. Looks better than Mikey did in it.)
Just One. That is if it is the REAL Jesus the One Just One. And how many lightbulbs would Jesus need? Just One. For Just One lightbulb blessed by the hand of Just One Jesus the One Just One would light the whole World. Forever. Just One. Boy those folks at Sylvania would be upset.... (submitted under some sort of sort of religious trance by The frenzied and fanatical Sister Aimee Faye Baker Eddy of the Foursquare Pentecostal Assembly of Jesus Scientist who was neked as a jay bird when she submitted it)
Just one but by the time his followers were done talking about it you'd think that he screwed in every lightbulb on the planet. (submitted by The Enlightened Despot wearing 100% Cotton)
One to actually screw it in and 599 authors who transcripted the bible to to tell how their Jesus did it more stunningly by magic. (submitted with anthropological sensitivity by the Unknown Apostle wearing Just the Facts, Ma'am.)
Only one, plus 10 million sadistic followers to oppress the Pagans so bad that we STILL are being opressed by the christians. (submitted by the hopelessly reduntant WiccanGuy who was obviously to opressed to be wearing anything at all.)
One stupid. He'd shoot the lightbulb into the socket with a spud gun. And I think the plural form of Jesus is Jesi. (submitted from an obviously higher plain of existance than the rest of us stupid peons by Commander J. Waffletruck wearing 100% Cotton.)