Probably the third century CE.
Most of Jamestown's inhabitants were Christians.
There is no early Christian art. Until Constantine legalized Christianity in the 4th century, most Christians would have considered religious art as possible Idols and thus prohibited.
There are a huge number of gay Christians. Most gay Christians are closeted, but the Metropolitan Community Church and the United Church of Christ have large gay followings.
By far, most of those persecuted or killed by Christians were . . . Christians! Most people asking and answering this question are ignorant that there are distinctions among people who call themselves Christians. To answer this question properly one must understand that there are Catholics and there are Protestants, and both call themselves Christian. Most of those killed by Catholics after the Reformation were Protestant Christians. And a few number of people--a handful, really, in total history--have been killed or persecuted by Protestants--the fewest number compared to any group. So the very common rebuttal to the statement that Islamic terrorists are killing people in a religious fervor, or that many millions were killed by communists, "Christians killed a lot, too, in the Dark Ages!" is a non-sequator.
Betlehem, I would assume, as it is believed by most Christians to be the birthplace of Jesus Christ.
Christmas is about celebrating the birth of Jesus Christ. Christians acknowledge Jesus as the Saviour of the world, and while he most likely was not born on 25 December, it is the day Christians adopted from ancient pagan festivities to celebrate the birth of Christ.
Mt. Vesuvius
If by "most forms of Christianity" you mean the form practiced by most Christians, that would be Roman Catholicism, and that makes the sacrament Eucharist. Other Christians, especially Protestants, do not believe in transubstantiation. That is to say, they do not believe that they actually take Christ into the body of the believer.
Ethnically Jewish people who are Christians or Messianic Jews. It is worth noting that most Jews consider Messianic Jews to be Christians.
Most-but not all-Christians say no. Most Christians believe that Jesus retained divinity throughout his life on Earth. Saint Paul says, "Christ did not deem equality with God as something to be grasped; rather, he emptied himself," meaning that Christ was a divine being who "adopted" humanity for himself along with his divinity. However, some Christians (including me) believe that Christ was not God. He was the Messiah, but otherwise a separate person from God (to say that Jesus is the Messiah is not the same as saying that Jesus is divine).
Christmas is about celebrating the birth of Jesus Christ. Christians acknowledge Jesus as the Saviour of the world, and while he most likely was not born on 25 December, it is the day Christians adopted from ancient pagan festivities to celebrate the birth of Christ.
were poor and lived in filthy crowded conditions