Sanctification begins in salvation. One might cease in their fellowship with God by becoming a carnal Christian, but never can a believer lose their salvation. Just as God gives human life, he gives spirit life. He describes salvation as a rebirth. We are saved from eternal condemnation by that rebirth. We are not repetitively or continuously born anew, we are only reborn once. We might repent and return to Him repetitively, but salvation is a one time event. Regeneration is not within the power of the church to bestow to any unbeliever.
-A8