Hi Brother Bob! One can think they are saved, and then supposedly renounce it, but this could just be one who doesn't know what he are doing. First it has to be decided if the person is genuine in deciding for salvation or not. One could genuinely believe he is saved, and if it is true, he cannot renounce nor will ever want to reject it, because of Phl 2:13). When God works in someone, it's permanent, but without knowing this, there is only confusion; and God does this "work" in everyone who is truly saved. Everyone would be saved if we could pray that they be saved, for God wouldn't isn't prejudice (Luk 20:21; Act 10:34; Rom 2:11; Gal 2:6; Eph 6:9; Col 3:25; 1Pe 1:17). It must be one who desires to be right with God first, then He saves them. It's only fair that one must desire to believe in Him before He will save them. The concept that God, for some reason, only saves certain people, is very confusing. Since "salvation hath appeared to all men," it's up to man to desire God; which we already know that most choose to be an unbeliever (Matt 7:13, 14).