I suppose a good number of other passages in the Bible also read like speculative literature, but the Christmas story seems to have compacted a number of speculative tropes. There are several angelic visitations, for example. Joseph had a conversation with an angel, and so did Mary. But before them was Zacharias, John the Baptist's dad, and his encounter with the angel of God in the temple. Most dramatic, and perhaps most well know, was the visitation of the shepherds, first by a single angel, then by "a multitude of the heavenly host."