And hereby we do know that we know him, if we keep his commandments. (4) He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him. (5) But whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him. (6) He that saith he abideth in him ought himself also so to walk, even as he walked.
It should seem, that it is Christ that is here spoken of as knowing him, because the Apostle had been speaking of Christ, in the preceding verses, as our Advocate and Propitiation; and as such, the way he saith by which we knew Christ, both in his Person, and in those blessed offices, is manifested in keeping his commandments. All which may he gathered from the Gospel, and which relate to his ordinances: and, as John dwells so particularly in this whole Epistle on the grace of love, as the fruit, and effect of God's love to the Church in Christ; it is possible, that he might have an eye to what the Lord Jesus had said in the days of his flesh, of a new commandment he gave them, to love one another. See John 13:34. But if the Apostle had a more general reference to the commandments of God, they are all comprized in that one comprehensive obedience, which our Lord, in his Commentary, gave the Jews; John 6:28-29.