Christianity began when Jesus traveled to Jerusalem to talk about Christianity and believing in God. When he got there he had his "Last Supper" with his disciples to celebrate the Jewish holy days of the Passover. In Jerusalem, he talked more about Christianity to start it and to spread. The Roman soldiers started getting angry at Jesus because the Christians refused to worship Roman Emperors and their religion. The Romans ended up deciding to crucify Jesus to kill him so he could stop making the themselves look bad. 3 days after he died he rose from the dead and appeared to some of his disciples. That proved that what Jesus said was right, Christianity began, and people kept spreading and talking about Christianity.