Douglas Moo warning us about a wrong conclusion we can draw from believing in the perseverance of the saints:
But the danger is that such a theological position will lead to smug satisfaction, a presumption on God’s grace. Belief in eternal security must not lead to unconcern about holiness of life. We may believe that God promises to preserve his saints to the end, but we must also recognize that it is in that very perseverance that the saints are recognized (see Heb. 3:6, 14). Thus we Christians are called to respond to the truth about God that we learn and are warned about the consequences if we fail to do so. . . .
“Cheap grace” is endemic among contemporary evangelicals. We constantly hear that God loves us, that Christ’s blood covers our sins, that “if we confess our sins, he is faithful and just and will forgive us our sins” (1 John 1:9)—precious promises, not to be toned down for a minute. The problem is that we don’t often enough hear that God is holy and terrible in his majesty, that he is just and cannot abide sin, that “we must all appear before the judgment seat of Christ, that each one may receive what is due him for the things done while in the body” (2 Cor. 5:10). The litmus test of our Christianity is not how much we know but the degree to which what we know affects our attitudes and actions. We Calvinists must be extremely careful that we do not allow our belief in or teaching about eternal security to remove or lessen the responsibility that God places on our shoulders to grow in the grace he so richly makes available.
Moo, Douglas J. (2011-02-22). 2 Peter, Jude (NIV Application Commentary, The) (Kindle Locations 3533-3547). Zondervan. Kindle Edition.