²⁴The one who keeps His commandments abides in Him, and He in him. We know by this that He abides in us, by the Spirit whom He has given us.

The theme of abiding weaves through the truth of believing in Christ. Abiding in Him is not just a mental assent. Belief in our Lord, as John frames it, involves an ongoing dynamic of life, not a static event in the past. It is a continuous trust in Him, resting in Him, relying on Him, living for Him, walking in Him. We continuously go to Him to draw our daily nourishment in the Spirit.

To be sure, eternal life has a beginning in our time-dependent experience, when God regenerated us into new creatures in Christ (2 Cor. 5:17), when we passed from death into life (John 5:24), from the kingdom of darkness into the realm of light (Col. 1:13), from being enemies of God to being His children (John 5:10, John 1:12). But John is writing here not just about a past event but an ongoing life of faith. He calls it “abiding” in Christ. In his gospel account (John 15:1–11), we find the metaphor that likens this faith dynamic to branches abiding in the vine as an image of us finding our source and substance in Him.

This kind of faith goes beyond saving us; it provides continuous life in Christ. John is not concerned here about whether failing to abide in Christ will result in loss of eternal life. He deals with that subject elsewhere (we understand Scripture to teach that a genuine believer cannot lose eternal life—God does not break His promise to us, as He stated in 1 John 2:25).

However, and this is a big caveat, we must continue obeying Christ now that we are saved, that is, to live the life of our salvation. If we keep His commandments, then we are abiding in Him. Of course, we are free not to obey Him and thus, not abide in Him, but why would someone who genuinely believes in Christ want to do that? That makes no sense. What would it then mean to be a follower of Christ, a disciple, one who believes that God gave us Jesus as the supreme act of love for us? To go against all this would serve to call into question the genuineness of the faith professed!

John appeals to the inner witness of the Spirit. Faith is not validated by a rigid adherence to the OT Law of Moses or a Christianized version of law-keeping. We know we abide in Christ and He in us through the spiritual activity of the third member of the Trinity, testifying to us on the spiritual level. To all who argue that this is nebulous, esoteric, and unverifiable, we would question whether they have genuinely experienced having the Spirit in their lives. To true believers, the work of the Spirit is persuasive. That is the spiritual reality.

Lord, my deepest desire is to genuinely abide in You and Your Spirit in me.