1 JOHN 1 OVERVIEW
The Incarnation and confession.
1 John presents an interesting situation for people studying the Bible: the book is grouped with the epistles of the apostle, and we even generally call it an epistle, and yet it wasn't really a letter—it was instead simply a teaching meant to be distributed among the churches of Asia Minor. The book was written to counter the false teachers and former Christians who attacked the Orthodox faith.
The Holy Apostle John opens this book with a very short first chapter—a mere ten verses—that nonetheless discusses two immeasurably deep topics: the Incarnation, and the importance of repentance and confession.
The first three verses of 1 John are comprised of a single, incredibly rich sentence that it would be helpful to briefly summarize: the gospel proclaimed by the apostles is focused upon—and rooted in—Jesus Christ. Jesus, the eternal Son of God, became human, and therefore was seen, heard, and touched by His disciples, who then declared that He is the Word of life for all who believe in Him. Furthermore, the readers and hearers of this book could have fellowship with these disciples, and all could have fellowship with God the Father and God the Son. This, St. Hilary of Arles says, is why the apostle wrote this book, "The fullness of joy comes when we are in fellowship with the apostles, as well as of the Father, Son and Holy Spirit" (see 1:4).
St. John continues that, in addition to being the Word of life, Christ is also light (1:5); this means, according to Blessed Theophylact, that He sustains all living things, gives spiritual life to humans, and enlightens the soul. Since God has no darkness in Him, we likewise cannot walk in the darkness of sin—to do so would make us liars (1:5-6). The key, then, is to walk in the light and have fellowship with other Christians, and through Christ be cleansed from all sin (1:7). Venerable Bede puts it like this:
The righteous walk in the light when they do good works and thereby go on to better things...John also gives us an indication of how we can know that we are on the right track, and that is whether we rejoice in the link of brotherly fellowship which we have with those who are journeying along with us toward the pure light.
Among the many differences between God and us is that, while in Him is no darkness at all (1:5), we humans are instead sinners (1:8). In fact, if we say that we have not sinned, we are implying that God is a liar (1:10)! Needless to say, people who would claim such a thing are not Christians (1:10). We should therefore confess our sins and be forgiven and cleansed by God (1:9).
St. Ephraim the Syrian powerfully describes both the attitude with which we should confess our sins, and God's response to our confession, "Cry out, O sinner, with all your might, and spare not your throat; for your Lord is merciful and loves those who repent. As soon as you return, your Father will come out aforehand to meet you, and rejoice in you."
Notice how the apostle concludes: if we claim to have no sin—if we do not take our sinfulness seriously—then God's word is not in us (1:10). Archimandrite Sophrony explains that each of us faces a crucial choice:
We have diametrically opposite alternatives: either to refuse God—the very essence of sin—or to become sons of God. Because we are made in the likeness of God we naturally desire the divine perfection which is in our Father. And when we follow Him we are not submitting to the dictates of some extraneous power: we are merely obeying our own impulse to assimilate His perfection (see Matthew 5:48).