1 John 1:6

“If we say that we have fellowship with him, &c.] The Alexandrian copy reads, “for if we say”: that is, if any profess to be partakers of the divine nature, to be like unto God, and to have communion with him, to have the light of his countenance, and the discoveries of his love: and walk in darkness; in the darkness of sin, ignorance, and unbelief, or are in a state of unregeneracy and blindness; whose understandings are darkened, and they know not God in Christ, nor have any true sight and sense of themselves, their sin and danger; and are ignorant of Christ and his righteousness, and the way of salvation by him; and are strangers to the Spirit of God, and the work of his grace; and are…”

“say--profess. have fellowship with him-- (Jo1 1:3). The essence of the Christian life. walk--in inward and outward action, whithersoever we turn ourselves [BENGEL]. in darkness--Greek, "in the darkness"; opposed to "the light" (compare Jo1 2:8, Jo1 2:11). lie-- (Jo1 2:4). do not--in practice, whatever we say. the truth-- (Eph 4:21; Joh 3:21).”

“If we say that we have fellowship uith him - If we reckon ourselves among his friends, or, in other words, if we profess to be like him: for a profession of religion involves the idea of having fellowship with God, (compare the notes at 1 John 1:3), and he who professes that should be like him. And walk in darkness - Live in sin and error. To “walk in darkness” now commonly denotes to be in doubt about our religious state, in contradistinction from living in the enjoyment of religion. That is not, however, probably the whole idea here. The leading thought is, that if we live in sin, it is a proof that our profession of religion is false. Desirable as it is to have the comforts of religion,…”

“If we say - Either with our tongue, or in our heart, if we endeavour to persuade either ourselves or others. We have fellowship with him, while we walk, either inwardly or outwardly, in darkness - In sin of any kind. We do not the truth - Our actions prove, that the truth is not in us. 1 John 1:7”

“1:6 This is the first of several instances in which John challenges the claims of the Gnostics, who had broken away from the apostolic fellowship and were thus living in spiritual darkness. They claimed to have fellowship with God but did not express his character, which is light. Jesus had warned the Jewish leaders of his day not to let the light they thought they had be darkness (Matt 6:23)—their religious beliefs had blinded them to the spiritual illumination they could have received from Christ. In like manner, these Gnostic teachers thought they were enlightened but were actually darkened by their so-called illuminations. They claimed to have spiritual experiences from God, yet they…”

“If: Jo1 1:8, Jo1 1:10, Jo1 2:4, Jo1 4:20; Mat 7:22; Jam 2:14, Jam 2:16, Jam 2:18; Rev 3:17, Rev 3:18 fellowship: Jo1 1:3; Psa 5:4-6, Psa 94:20; Co2 6:14-16 walk: Jo1 2:9-11; Psa 82:5; Pro 2:13, Pro 4:18, Pro 4:19; Joh 3:19, Joh 3:20, Joh 11:10, Joh 12:35, Joh 12:46 we lie: Jo1 1:10, Jo1 4:20; Joh 8:44, Joh 8:45; Ti1 4:2 do not: Joh 3:21 1 John 1:7”