The Gnostic false teachers were trying to undercut the confidence of the Christians of John’s audience. He wrote that they may know their standing with God. The end of chapter 2 affirmed that, “everyone who practices righteousness is born of Him” (2:29). It is this fact that John expounded upon with such excitement.
To be born of God is to be a child of God. “What manner of love the Father has bestowed upon us” (v. 1)! In both indescribable quality, and immeasurable quantity, God’s love has been given to us in the relationship we enjoy as His children. This is the ultimate privilege and gift! However, despite the wonderful implications of such a fact, the world misses it completely. They do not see one who possesses and is being transformed into the Divine nature (cf. 2 Peter 1:2-4). They see a foolish man (cf. 1 Corinthians 1:26-31). Therefore, Christians are mistreated. This happens because they could not even see the glory that is the Son of God! They hated Him because they knew Him not, and they will hate His brethren the same (cf. John 15:18-25).
Yet, the Christian, the one who “practices righteousness,” is truly a child of God. He is in fellowship with the pure and almighty Divine One. As such, the Christian is like Him. But, this is not noticeable in a carnal form, for God is spirit (cf. John 4:24). However, when Jesus comes “to be glorified in His saints” (2 Thessalonians 1:10), “we shall be like Him.” The one who has such a hope to be found in the pure and glorious state as Christ is to work to that end. It is NOW that we are children of God, and we are to act accordingly.