from the beginning. Note the similarity between the opening verses of John's gospel and his first epistle, both starting with a reference back to creation. The gospel of John looks back before the beginning of time, when only God existed, and Jesus Christ was God. His epistle, on the other hand, proceeds forward from that beginning of time (Genesis 1:1) to the incarnation of the eternal “Word,” which became “the Word of life,” the manifestation of the Father in “His Son Jesus Christ” (xTerm 1:3).

we. The author uses the plural “we,” referring undoubtedly to the twelve apostles, but later uses the first person singular when his epistle becomes more personal (e.g., xTerm 2:1). In any case, it is obvious that the author is the beloved disciple, John, even though he never identifies himself by name. The similarity in vocabulary between John's gospel and his epistles is strikingly obvious. For example, the word “know” occurs more in the Gospel of John than in any of the other gospels, and occurs in xTerm more than in any other epistle. Exactly the same phenomenon is noted for many other vocabulary words. These include such words as love, light, truth, fellowship, commandment, abide, witness, eternal, manifest, keep, overcome, beginning, father, son, and others.

heard. John was writing this epistle late in the first century after all the other apostles were dead. Tradition suggests he was writing from Ephesus, where he served many years as bishop and pastor, possibly intending his letter to be circulated among all the churches of the region, including the seven churches of Revelation 2 and 3. He stressed to his readers of the younger generation that he and the other apostles had actually heard Jesus speak (note John 5:24), seen Him with their own eyes (John 1:18), “beheld” Him in His glory (John 1:14) and handled Him with their own hands (Luke 24:39).

life was manifested. When “the Word of life” (xTerm 1:1) “became flesh” (John 1:14), that eternal life “was manifested unto us.” Because we have been shown life in God as it really is, when we have seen Christ, we know that He is able to convey that same eternal life to us.

fellowship. “Fellowship” as used in Scripture does not refer to mere social companionship or camaraderie, as we tend to use the term today. The same word is translated “communion” (e.g., 1 Corinthians 10:16; 2 Corinthians 6:14). The basic meaning is “joint participation in things held in common.” The fellowship we can have with the Father through the Son (John 17:22, 26) is the same fellowship we as believers can have with one another.

God is light. Since God is light, dwelling in light (1 Timothy 6:16), He did not have to “create” light, but simply say: “Light, be!” (Genesis 1:3). On the other hand, He did create darkness (Isaiah 45:7) as the initial state of the unformed and uninhabited earth (Genesis 1:2). When light appeared to disperse the darkness, it could thereby become a model of the shining of spiritual light into a soul born in the darkness of innate sin (2 Corinthians 4:6). Physically, God is the light of shining glory; intellectually, He is the light of truth; and morally He is the light of holiness. He is also the light of life (John 1:4) and of true guidance (John 8:12).

do not the truth. Note that the truth is not only something we should believe and teach, but also something we should do!

fellowship one with another. That is, we are in fellowship with the Lord, and therefore also with other believers who are in fellowship with Him. Since there is no darkness in God, if we truly walk in His light, there can be no reason for any error, sin, or ignorance of His will on our part.

cleanseth us. Literally this could read “keeps on cleansing us from all sin.” The blood of Christ was not like that of other men, for it was “the precious blood ... without blemish and without spot” (1 Peter 1:19), uncontaminated either by inherited genetic mutations or inherent sin. Somehow, after it was all poured out at the foot of the cross (John 19:34) in atonement for our sins (Hebrews 9:22-28), “by His own blood [Christ] entered in once into the holy place, having obtained eternal redemption for us” (Hebrews 9:12).

all sin. All sin, whether known or unknown, is cleansed by His blood, as we walk in fellowship with Him.

deceive ourselves. The heresy of “perfectionism”—that is, the claim that our sin-nature has been completely eradicated, so that we no longer commit sin—is self-deception. It is related to the Gnostic heresy of the time which claimed that the soul had been set free from one's sinful flesh.

confess our sins. To “confess” one's sins does not mean merely to confess one's sins in general, but rather to identify them specifically, and then to agree with God as to their specific sinful character, thus in reality repenting (that is, changing one's mind) about them and viewing them as God does. Since Christ's blood has already been shed to cover them, He is faithful to His Word and provides forgiveness in perfect justice.

cleanse us. The “confession” of this verse is not merely a pat formula that one can glibly apply and then all is well. When God forgives our sins, He also expects to “cleanse us from all unrighteousness” (not just from the penalty of unrighteousness). The Greek word for “cleanse” is katherizo (from which we get our English word “catharsis”) and is often translated “purify” and even “purge.”

have not sinned. To say either that we “have no sin” (xTerm 1:8) or “have not sinned” (xTerm 1:10) is presumptuous, blasphemous and false. Those who make such claims may deceive themselves, but others can easily discern sin in them.