Premise: Shadrach, Meshach and Abednego are figures from chapter 3 of the Book of Daniel, three Hebrew men thrown into a fiery furnace by Nebuchadnezzar, king of Babylon, when they refuse to bow down to the king's image; the three are preserved from harm and the king sees four men walking in the flames, "the fourth ... like a son of God".
Hypothesis: the Book of Daniel was released in the year 500 CE