1 JOHN 3 OVERVIEW
Love and truth.
The Holy Apostle John begins 1 John 3 by reminding us of a tremendous blessing that has been given to us: we are called the children of God (3:1). Fr. Lawrence Farley shows us the significance of this when he says, "That in baptism God should call and adopt us as His own children—we who have sinned and spurned His love times without number—how astonishing and undeserved is this love!”
At the same time, since non-Christians did not recognize the Son of God, it should be no surprise that they do not recognize us as God's children (3:2). Even so, while even we do not know everything we will be in the age to come, we nonetheless know that we will be transformed to be like Christ when we finally see Him (3:2). St. Symeon the New Theologian explains this transformation in this way:
The Son of God has become Son of Man in order to make us...sons of God, raising our race by grace to what He is Himself by nature, granting us birth from above through the grace of the Holy Spirit and leading us straightway to the kingdom of heaven, or rather, granting us this kingdom within us (Luke 17:21), in order that we should not merely be fed by the hope of entering it, but entering into full possession thereof should cry: our 'life is hid with Christ in God' (Colossians 3:3).
There is an important stipulation involved in being a child of God: we must not sin (1 John 3:4-6). In fact, those engaged in sinful lifestyles demonstrate that, rather than being children of God, they are instead children of the devil (3:8, 10). The key is that God dwells in the Christian (see Ephesians 3:17; John 14:23), thereby enabling him or her to refrain from sinning (1 John 3:9).
The apostle then transitions from discussing sin to return to the main subject of the previous chapter: the importance of loving one another. Practicing righteousness is inherent in being a child of God, he says, and directly related to this is loving one's brother in Christ. Hateful people are like Cain, who murdered his brother, Abel (3:12; see Genesis 4:1-16); they are likewise murderers who abide in death (3:14-15).
In contrast to such hatefulness, Christians should feel and demonstrate love for others because we know true love—we are blessed by the love Christ showed by laying down His life for us (3:16). We should therefore show similar love for those around us, providing for their needs (and even sacrificing ourselves if necessary) (3:17-18). St. John of Kronstadt sums it up like this,
God is long-suffering and merciful to you: this you experience many times every day. Be long-suffering and merciful to your brethren, also fulfilling the words of the Apostle, who thus speaks of love before everything: 'Love suffers long and is kind' (1 Corinthians 13:4). You desire that the Lord should rejoice you by His love, rejoice on your part the hearts of others by your tender love and kindness.
St. John says we are to love in truth, and that doing so confirms we are of the truth (3:18-19). This was—and is—important, because false teachers and heretical doctrines were causing some believers to doubt the truth of Christianity (the same thing, of course, happens today). By living in the love of God and following Christ's commandments, we can confirm—even in the midst of doubts—that we are true Christians (3:20-23). Furthermore, Blessed Theophylact says, "If we obey God's commands, then our obedience will bear fruit, for we shall receive whatever we ask for" (see 3:22). This is because, the apostle tells us, people who follow God's commands remain in God, and God remains in them (3:24).