From the time that Bloom picks up a religious throwaway paper in "Lestrygonians", he is compared to the prophet Elijah. In particular, at the end of "Cyclops," as Martin Cunningham's carriage pulls away from Barney Kiernan's pub and the citizen yells angrily after Bloom, Joyce invokes biblical imagery of the ascent of Elijah into heaven.
The passage goes:
When, lo, there came about them all a great brightness and they beheld the chariot wherein He stood ascend to heaven. And they beheld Him in the chariot, clothed upon in the glory of the brightness, having raiment as of the sun, fair as the moon and terrible that for awe they durst not look upon Him. And there came a voice out of heaven, calling: Elijah! Elijah! And he answered with a main cry: Abba! Adonai! And they beheld Him even Him, ben Bloom Elijah, amid clouds of angels ascend to the glory of the brightness at an angle of fortyfive degrees over Donohoe's in Little Green Street like a shot off a shovel. (12.561)
Elijah was a prophet in Israel about 900 years before Christ. He appears in both the Hebrew and the Christian Bibles, and is reported to have warned King Ahab that he would suffer great misfortune because he was the last of a line of Israelite kings that had upset God by worshipping other pagan gods. Like Moses, God parts a sea for him, except in Elijah's case it's the Jordan. And then halfway through his passage, a flaming chariot appears and Elijah ascends up to heaven in a whirlwind. In another similarity to Moses, Jesus actually appears to both Moses and Elijah during a Biblical episode that is known as the Transfiguration. To this day, some people hold that the return of Elijah will precede Jesus' own return to earth.
The Elijah correlation gets into the earth that is tilled by literary scholars, but on a basic level it emphasizes the interplay between the Jewish and the Christian faiths. In the "Cyclops" episode, where Bloom is being persecuted by a narrow minded Irish Catholic, the imagery undermines the citizen's attacks and shows how foolish it is to be prejudiced against Bloom on the basis of his faith.
To an extent, you could also argue that Bloom functions as something of a prophetic figure. After all, it is Bloom, not Stephen, who first preaches the importance of love, which is so central to Ulysses.