Chapter two, beginning with verse three, presents the first of six “by this we [will] know” statements (1 John 2:3, 5; 3:19, 24; 4:13; 5:2) regarding how we know that we know God or are in him. In chapter two we know this “if we keep his commandments…[and] obey his word” (1 John 2:3, 5). Obedience to the Savior (not just obedience to a set of rules) is a clear indication that a person truly knows God, because an unbeliever walks in darkness, not in the light. However, again, 1 John 2:6 encourages that the believer “ought to walk” this way. Those who require the spiritual ideal presented in 1 John to be the continued real experience for all believers at all stages of growth as proof of salvation are misusing the Scriptures. Even as he presented the ideal, John did so with grace and encouragement, knowing that we do not always live up to that standard.
In 1 John 2:7-17 John insisted that believers are to love God and that love should extend to fellow Christians. Not loving (or “hating”) other believers is likened to stumbling and groping around in the dark, because that Christian is not walking in Christ’s light. Jesus himself said, “Everyone will know by this that you are my disciples – if you have love for one another” (John 13:35).
Another proof that a believer does not love God properly is shown in his love for “the world or the things in the world” (1 John 2:15). Because “the whole world lies in the power of the evil one” (1 John 5:19), spiritual growth should cause us to love God more while we love this world less. This reflects a worldview based in eternal things rather than temporal things.
Like several other writers before him (Paul, Peter, and Jude), John knew that false teachers are devastating to Christians. Because of how late he wrote (probably in the A.D. 90s), John saw these false teachers no longer just sneaking into the Church (Jude 4) but boldly teaching false doctrine in the Church. He said there were “many” of them (1 John 2:18) who had exerted their influence strongly enough that they had left the Christian fellowship and had drawn others away with them. John insisted that there is one “litmus test” of basic orthodoxy (1 John 2:22; 4:1-3): Jesus is the Christ (recognition of deity) who had come in the flesh (recognition of humanity). Although much other doctrine is important, agreement on nothing else matters if there is disagreement on this point. This was the teaching of Jesus himself, the apostles, and the indwelling Holy Spirit (1 John 2:27).