To “abide” is to live, continue, or remain; so, to abide in Christ is to live in Him or remain in Him. When a person is saved, he or she is described as being “in Christ” (Romans 8:1; 2 Corinthians 5:17), held secure in a permanent relationship (John 10:28–29). Therefore, abiding in Christ is not a special level of Christian experience, rather, it is the position of all true believers. The difference between those abiding in Christ and those not abiding in Christ is the difference between the saved and the unsaved.
Abiding in Christ is taught in 1 John 2:5–6, where it is synonymous with “knowing” Christ (verses 2 and 3). Later in the same chapter, John equates “remaining” in the Father and the Son with having the promise of eternal life (verses 24 and 25). Biblically, “abiding in,” “remaining in,” and “knowing” Christ are references to the same thing: salvation.
The phrase abiding in Christ pictures an intimate, close relationship, and not just a superficial acquaintance. In John 15:4–7, Jesus tells His disciples that drawing life from Him is essential, using the picture of branches united to a vine: “Abide in Me, and I in you. As the branch cannot bear fruit of itself unless it abides in the vine, so neither can you unless you abide in Me. I am the vine, you are the branches; he who abides in Me and I in him, he bears much fruit, for apart from Me you can do nothing. If anyone does not abide in Me, he is thrown away as a branch and dries up; and they gather them, and cast them into the fire and they are burned. If you abide in Me, and My words abide in you, ask whatever you wish, and it will be done for you.” Without that vital union with Christ that salvation provides, there can be no life and no productivity. Elsewhere, the Bible likens our relationship with Christ to that of a body with a head (Colossians 1:18)—another essential union.
Some people take the warning of John 15:6 (branches that do not abide in the vine are thrown away and burned) to mean that Christians are always in danger of losing their salvation. In other words, they say it’s possible to be saved but not “abide,” in which case we would be cast away. But this could only be true if “abiding” were separate from salvation, referring to a state of intimacy with Christ we must strive to attain post-salvation. The Bible is clear that salvation comes by grace and is maintained by grace (Galatians 3:2–3). Also, if a branch could somehow fall away from the vine, resulting in the loss of salvation, then other, very clear passages of Scripture would be contradicted (see John 10:27–30).
It is best to interpret the True Vine metaphor this way: Jesus is the True Vine, obviously. The branches who “abide” in Him are the truly saved—they have a real and vital connection to the Savior. The withered branches who do not “abide” in Him are the unsaved pretenders who feigned an attachment to the Vine but drew no life from Him. In the end, the pretenders will be seen for what they were: hangers-on who had no authentic attachment to Jesus. For a while, both Peter and Judas seemed identical in their walk with Christ. But Peter was attached to the Vine; Judas was not.
John restates the withered-branch principle this way: “They [people now opposed to Christ] went out from us, but they did not really belong to us. For if they had belonged to us, they would have remained with us; but their going showed that none of them belonged to us” (1 John 2:19).
One of the proofs of salvation is perseverance, or sustained abiding in Christ. The saved will continue in their walk with Christ (see Revelation 2:26). That is, they will “abide” or remain in Him. God will complete His work in them (Philippians 1:6), and they will bring forth much fruit to the glory of God (John 15:5). Those who fall away, turn their backs on Christ, or fail to abide simply show their lack of saving faith. Abiding is not what saves us, but it is one of the signs of salvation.
Proofs of abiding in Christ (i.e., proofs that one is truly saved and not just pretending) include obedience to Christ’s commands (John 15:10; 1 John 3:24); following Jesus’ example (1 John 2:6); living free from habitual sin (1 John 3:6); and the awareness of a divine presence within one’s life (1 John 4:13).