Regeneration is required for salvation. Regeneration is mysterious, operating apart from our sight. Regeneration precedes faith. Regeneration is the sovereign and immediate work of God. But that is not all that the Bible says about regeneration. We must now consider one final aspect of the biblical teaching on the matter—namely, the permanence of regeneration. Looking at the entire scope of divine revelation, we see that regeneration lasts forever.
Many passages of Scripture tell us that once the Holy Spirit renews us and grants us faith, He preserves us in that state for all eternity. Christians can fall into grievous sin. Some may even deny the faith for a time. However, the Lord never allows one of His true, reborn children to fall away finally. If a person with authentic faith seems to fall away, he will return to Christ before he draws his final breath.
Philippians 1:6 is one of the most important and clearest texts on this subject. Paul asserts that God will certainly bring to completion the good work that He begins in us. We need not doubt that our Creator will preserve us unto glory. He never abandons the work of renewal that He begins in regeneration, but He sees it through to glorification. In truth, we would be without hope if it were otherwise. Left to ourselves, none of us would continue in a state of grace and faith. Sin is real and powerful, and it leads only to death (Rom. 6:23). Without the Lord’s preserving work, the sin that remains would overtake us and snuff out any spiritual life that we have. But God preserves His children. This is not a passive work wherein we just sit back and relax. The Apostle also tells the Philippians to work out their salvation in fear and trembling (Phil. 2:12). Those who have been born of God seek to love and serve Him. Ultimately, however, this seeking comes from the Lord. Paul also tells us that God is at work in us to will and to work for His good pleasure (v. 13). His power and grace are what keep us in the faith, not our efforts.
Nevertheless, we cannot grow complacent. When we have sinned, we must repent and return to the Lord, knowing that He will certainly restore us (1 John 1:8–10). Those who continue in conscious sin, thinking that grace will abound, have misunderstood grace and likely have never truly believed in Christ in the first place (Rom. 6:1–4). Furthermore, we must pray for those who seem to have fallen away. Until they die, there remains hope for their return to Christ and His church. We cannot write anyone off as unsavable.