When a wayward youth is later reconciled with his or her parents, there's always the possibility the youth will revert to the former rebellious state. He or she would again be alienated from the parents. It would be a self-inflicted alienation, to be sure, but nevertheless a real one. In fact, the parents' displeasure might even be stronger the second time around. This points to a significant difference between a reconciliation between human beings and our reconciliation to God.
Our reconciliation to God is permanent and eternal. Because Christ accomplished it for us, there's no possibility it can ever be undone. Though we continue, even as believers, to do those things that in themselves deserve God's displeasure, we can never revert to a state of divine alienation. For the sake of Christ, God will always accept us. And even when God deems it necessary to discipline us for persistent disobedience, he always does so out of love to restore us to the way of obedience (Hebrews 12:4-11).
This reconciliation does—in fact, it must—affect the way we live. The very nature of our salvation guarantees that we will not continue in an absolute state of sin and rebellion against God. He not only saves us from sin's guilt and consequent alienation; he also delivers us from sin's reign and continues to work to progressively free us from sin's activity in our lives. However, in the midst of God's work and our struggle with indwelling sin, we must always keep in mind that our status of favor and friendship with God is always, and ever will be, based on the objective work of Christ for us as our representative and substitute. We have been forever reconciled to God through the death of his Son. - Jerry Bridges
God has called every Christian to a holy life. There are no exceptions to this call. This call to a holy life is based on the fact that God himself is holy. Holiness is nothing less than conformity to the character of God.
Holiness in Scripture describes both the majesty of God and the purity and moral perfection of his nature. Holiness is one of his attributes—an essential part of the nature of God. His holiness is as necessary as his existence—as necessary, for example, as his wisdom or omniscience. Just as he cannot but know what is right, so he cannot but do what is right.
The absolute holiness of God should be of great comfort and assurance to us. If God is perfectly holy, we can be confident that his actions toward us are always perfect and just. We're often tempted to question God's actions and complain that he is unfair in his treatment of us. This is the devil's lie, the same thing he essentially told Eve: "God is being unfair to you" (Genesis 3:4-5). But it is impossible in the very nature of God that he should ever be unfair. Because he is holy, all his actions are holy.
We must accept by faith the fact that God is holy, even when trying circumstances make it appear otherwise. To complain against God is in effect to deny his holiness and to say he is not fair. As Stephen Charnock said, "It is less injury to him to deny his being, than to deny the purity of it; the one makes him no God, the other a deformed, unlovely, and a detestable God . . . he that saith God is not holy speaks much worse than he that saith there is no God at all." (Excerpt taken from Jerry Bridges' The Pursuit of Holiness)