If I sin, will I lose my salvation?
Can you conceive of somebody adopting a child and then throwing it out on the street because it falls while learning to walk? When we are saved, we are adopted into the family of God. We must, out of love on one hand and godly fear on the other, seek to live a life that is pleasing to Him. But the idea that one act of sin would cause someone to be thrown out of God’s family is not in the Bible (I John 1:7, 9). However acts of sin or rebellion will take away the joy of your salvation. When David sinned he had no joy, because he had rebelled against God (Ps. 51:12). He said, "Do not take Your Holy Spirit from me" (Ps. 51:11). Even though he had committed adultery and had been responsible for an innocent man’s death, by this clear statement we are shown that he still had the Holy Spirit. Though punishment came due to his sin, nevertheless, God forgave and loved him because David was repentant before the Lord.
If one continues in a course of known sin, assurance of one’s salvation may be lost, but that is not the same as an actual loss of one’s salvation. When the Scripture says, "Whoever is born of God does not sin" (I John 5:18), the sense of the Greek is not that a Christian never commits an act of sin, but that he does not continue in a course of sin, refusing to confess and repent of his sins. A person born of the Spirit of God will be drawn back to repentance every time he sins.
Beyond that, we do read in Hebrews 10:29 that if somebody actually says the blood of Jesus Christ is a common (unholy) thing and renounces the salvation he has received, then that person may have lost it all. But the same book says, "But, beloved, we are confident of better things concerning you" (Heb. 6:9). It is very hard to believe that someone who has been born again would turn that far away from God.
But one might ask, if we are new creatures in Christ, why do we even still have the capacity to sin? The answer is that perfection for the Christian awaits us in heaved (I Cor. 15:54). Now, we are united with Jesus at salvation, but we are being progressively transformed into His image (2 Cor. 3:18). We are being changed throughout our lives, but there is no final moment, short of death, when the believer becomes sinless’ perfect (I John 1:8).
