I have written — Namely, 1 John 2:13. To you because ye know the truth — That is, to confirm you in the knowledge ye have already. Ye know that no lie is of the truth — That all the doctrines of these antichrists are irreconcilable to it.
Related Commentaries of 1 John 2:21
1 John 2:21
21 I have not written unto you because ye know not the truth, but because ye know it, and that no lie is of the truth.