The title Bel was given by the Babylonians to their idol Marduk (or Merodach) to show that he was their chief god. Bel-Marduk is equivalent to the Canaanite deity Baal. In Mesopotamian mythology, Bel won kingship among the gods by defeating Tiamat, the goddess of chaotic waters. His ascension symbolized Babylon's political dominance of the region. But prophets of Judah foretold the fall of Bel along with Babylon: Jeremiah speaks of a time when "Babylon is taken, Bel is put to shame, Merodach is dismayed" (Jer. 50:2).

In Bel and the Dragon, a second-century B.C. addition to the book of Daniel, the foolishness of the Babylonian belief that "Bel is a living God" (Bel 6) is revealed by Daniel. The Babylonians, according to this tale, set a feast each day before their idol and believed that Bel came at night to consume it. But one night Daniel secretly sifted ashes on the floor of the temple, and the next morning he pointed out priests' footprints to the king, proving the food had been secretly carried away.

{E2 Dictionary of Biblical People}