Second Coming
The Second Coming (sometimes called the Second Advent or the Parousia) is a Christian and Islamic belief regarding the future (or past) return of Jesus Christ after his ascension to heaven about two thousand years ago. The idea is based on messianic prophecies and is part of most Christian eschatologies.
Date of birth of Jesus
The earliest source stating 25 December as the date of birth of Jesus is likely by Hippolytus of Rome, written very early in the 3rd century, based on the assumption that the conception of Jesus took place at the Spring equinox which he placed on 25 March, and then added nine months – festivals on that date were then celebrated. 25 March would also roughly be the date of his crucifixion, which ancient Christians would have seen as confirming the date of his birth, since there was a notion that the great prophets were conceived into the afterlife on the same date they were conceived into the world. John Chrysostom also argued for a 25 December date in the late 4th century, basing his argument on the assumption that the offering of incense in Luke 1:8–11 was the offering of incense by a high priest on Yom Kippur (early October), and, as above, counting fifteen months forward. However, this was very likely a retrospective justification of a choice already made rather than a genuine attempt to derive the correct birth date.