How similar are angels to human beings?

Heavenly angels are more refined, holy, virtuous, obedient and can deliver messages to mankind in ways a human never could. They are stronger than men (Psalm 103:20; 2 Peter 2:11). Angels have a greater knowledge of everything  (2 Samuel 14:20).

"Bless the Lord, you His angels, who excel in strength, who do His word,
heeding the voice of His word" (Psalm 103:20).

"Whereas angels, who are greater in power and might, do not bring a reviling accusation against them before the Lord" (2 Peter 2:11).

"To bring about this change of affairs your servant Joab has done this thing; but my lord is wise, according to the wisdom of the angel of God, to know everything that is in the earth" (2 Samuel 14:20).