Writing to the Philippians, Paul says, “He who has begun a good work in you will perfect it to the end” (Phil. 1:6). Therein is the promise of God that what He starts in our souls, He intends to finish. So the old axiom in Reformed theology about the perseverance of the saints is this: If you have it—that is, if you have genuine faith and are in a state of saving grace—you will never lose it. If you lose it, you never had it.
We know that many people make professions of faith, then turn away and repudiate or recant those professions. The Apostle John notes that there were those who left the company of the disciples, and he says of them, “Those who went out from us were never really with us” (1 John 2:19). Of course, they were with the disciples in terms of outward appearances before they departed. They had made an outward profession of faith, and Jesus makes it clear that it is possible for a person to do this even when he doesn’t possess what he’s professing. Jesus says, “This people honors Me with their lips, but their heart is far from Me” (Matt. 15:8). Jesus even warns at the end of the Sermon on the Mount that at the last day, many will come to Him, saying: “Lord, Lord, didn’t we do this in your name? Didn’t we do that in your name?” He will send them away, saying: “Depart from Me, you workers of iniquity. I never knew you” (Matthew 7:23). He will not say: “I knew you for a season and then you went sour and betrayed Me. No, you never were part of My invisible church.” The whole purpose of God’s election is to bring His people safely to heaven; therefore, what He starts He promises to finish. He not only initiates the Christian life, but the Holy Spirit is with us as the sanctifier, the convictor, and the helper to ensure our preservation.