ἰσάγγελοι [1 verse]( adj pl masc nom) "Equal unto angels" is isaggelos, which means "like an angel." It is an invented word from isos, which means "equal" in size, strength, number, or rights and aggelos, which means "messenger" and "envoys."  This word is found nowhere else in ancient Greek, used only to describe people awakened from death. It is just a coincidence that it resembles "is angels" in English. If you believe in coincidences.