Man of God is a biblical title of respect applied to prophets, beloved religious leaders and even an angel and an Islamic title as well mostly for showing the humbleness and helplessness to God by humans. The term Man of God appears 78 times in 72 verses of the Bible, in application to up to 13 individuals:
The man from Judah who cried out against King Jeroboam of Israel (1 Kings 13:1 (twice), 4, 5, 6 (twice), 7, 8, 11, 12, 14 (twice), 21, 26, 29, 31), whose tomb King Josiah protected and preserved when he destroyed the idolatrous tombs in Bethel (2 Kings 23:16, 17) and whom some rabbis identify as Iddo (Sifre to Deuteronomy 342:4; Pesikta de-Rav Kahana 2:85; Zohar 2:64a)
The man who told King Ahab of Israel that Israel could defeat the Arameans (1 Kings 20:28) whom Sifre identifies as Micah (Sifre to Deut. 342:4), but who from context might also be Elijah
The man who warned King Amaziah of Judah not to go to war (2 Chronicles 25:7, 9 (twice)), whom some rabbis identify as Amoz (Sifre to Deut. 342:4; Seder Olam Rabbah 20)