What does 1 John 2:4 mean?
John continues his emphasis on obedience as evidence of fellowship with Christ. He raises the stakes by stating that those who defy God's commandments while claiming to know Him are liars. John has referred to liars already in this letter (1 John 1:10), and will repeat this theme several times. Only a liar says he has not sinned, or says he knows God while failing to keep His commandments. Only a liar denies Jesus is the Christ (1 John 2:22), or says he loves God but hates his brother (1 John 4:20).The implications of this have to be taken seriously. In John's Gospel, Jesus called Satan a liar (John 8:44). He referred to hostile, unbelieving religious leaders as liars (John 8:55). In Revelation 21:8, the "second death" of the lake of fire is the destiny of all liars. John says that those who claim to know God but do not obey Him are liars, and do not have the truth in them. Truth is used eight times throughout 1 John (1 John 1:6, 8; 2:4, 21; 3:18, 19; 4:6; 5:6).
As a result, this reference to truth has been interpreted both to include "what is correct," as well as the presence of Christ Himself. First John 5:6 calls the Holy Spirit truth: "the Spirit is the truth." A person who claims to know God, but does not live like it, reveals he is liar and does not have the truth in him. In its immediate context, John is referring to our fellowship relationship to God. In a broader sense, this is often interpreted as an indicator that those who live in defiance of Christ's commandments give evidence that they do not "know" Him—at all.
Given the context of 1 John, and the rest of Scripture, this cannot refer to any and all instance of sin. All believers still sin. Even hatred for one's brother is possible for a Christian (1 John 2:10). Rather, this points towards those who claim to walk with God but really do not. Whether or not such people have come to Christ is between them and God, but their actions show they are clearly not "walking with" God. For that reason, this verse has alternately been interpreted as a reference to fellowship with God, without implications of false conversion. Since Christians still have the ability to choose sin, it is possible for a Christian to choose wrong actions over right actions.
