根據基督教教義名詞，耶穌復活四十天后升上天堂。〈使徒行傳〉第一章載，耶穌在四十天之內多次向使徒顯現，此后，使徒見祂上升進入云端。基督教徒認為，耶穌升天有重大意義，這是因為他們相信，耶穌死而復活之后，要享榮耀并被高舉，而且祂已回到天父身邊。這一事情是為了指出耶穌和天父以及耶穌和信徒間的新關系。慶祝耶穌升天的儀式為全世界的信徒所遵循，這個慶祝儀式強調了基督的君王身分。從西元4世紀開始，將復活節（Easter）后第四十天，及圣靈降臨節的前十天訂為耶穌升天日。

In Christian belief， the ascent of Jesus into heaven 40 days after the Resurrection. The Book of Acts relates that， after several appearances to the Apostles over a period of 40 days， Jesus was taken up in their presence and hidden behind a cloud， a symbol of God's presence. The event is thought to indicate a new relationship between Jesus and God and between Jesus and his followers. The feast of the Ascension is universally observed by Christians， and its celebration emphasizes the kingship of Christ. Since the 4th century， it has been celebrated 40 days after Easter and 10 days before Pentecost.