Expositor's Bible Commentary Commentary 1 John 2:5

"but whoso keepeth his word, in him verily hath the love of God been perfected. Hereby we know that we are in him:" — 1 John 2:5 (ASV)

Next John states the positive side of knowledge. The one who “obeys his word” (a more comprehensive way of speaking of the Gospel, including both promises and commandments) finds God’s love “made complete” (GK 5457) in him. True knowledge of God does not end with speculative ideas, as for the Gnostics, but with obedience to the moral law and with the presence of God’s love in the believer. “Made complete” carries with it the idea of continuous growth and development; it describes both state and process. As obedience is practiced, so God’s love matures in us.