The fact that John does not tell us the identity of those on the thrones (persons? angels? both?) indicates that their identity is not important (though interesting possibilities are hinted at in Revelation 4:4; Matthew 19:28; 1 Corinthians 6:2; Ephesians 2:6). What is important is that they had “authority to judge.” Giving judgment is the task of a king (hence “thrones”) as he discerns right from wrong (2 Samuel 15:3–4; 1 Kings 3:16–28), vindicates the wronged and oppressed, and pronounces a sentence on the oppressor.
4 Then I saw thrones, and seated on them were those to whom the authority to judge was committed. Also I saw the souls of those who had been beheaded for the testimony of Jesus and for the word of God, and those who had not worshiped the beast or its image and had not received its mark on their foreheads or their hands. They came to life and reigned with Christ for a thousand years.