A.T. Robertson Commentary 1 John 5:21

"[My] little children, guard yourselves from idols." — 1 John 5:21 (ASV)

Yourselves (εαυτα). Neuter plural reflexive because of τεκνια. The active voice φυλασσετε with the reflexive accents the need of effort on their part. Idolatry was everywhere and the peril was great. See Ac 7:41: 1 Thessalonians 1:9 for this word.