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.