Bach's Christmas Oratorio is nothing like Handel's Messiah. Handel wrote a concert piece, intended for stage performance. Bach, on the other hand, composed a work in six sections, to be used in church services over six specific days from Christmas to the Feast of the Epiphany in January.
It'll take a few weeks, but we'll hear the complete oratorio on Mozart's Attic from this Thursday night through early January -- and of course there will be plenty of other music for the season as the holidays approach.