QUESTION: Please explain the verse that says, "If we say that we have no sin." How, then, is it possible for us to live without sin?
ANSWER: All men have sinned, i.e. all have transgressed God's rule of conduct given to man (Rom. 3:23, 1 John 3:4). To deny our sins is to deceive ourselves. Such deception results in a rejection of Jesus as our sacrifice for sins. Of this John writes, stating that "the blood of Jesus Christ his Son cleanseth us from all sin. If we say that we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness. If we say that we have not sinned, we make him a liar, and his word is not in us" (1 John 1:7-10). This is not to say, however, that it is impossible to live without sin. In fact, John writes as he does "that ye sin not" (1 John 2:1). The fact is that man has and does sin. But that he can live free of sin was proved by Jesus. "God sending his own Son in the likeness of sinful flesh, and for sin, condemned sin in the flesh" (Rom. 8:3). Jesus came in the flesh (Heb. 2:14, 17), became a sacrifice for sin (Isa. 53:10-12), and condemned sin in the flesh in that He demonstrated that man can resist temptation (Heb. 4:15). Sin is not of necessity but is wilful and therefore worthy of condemnation. Man is a sinner not because he was made a sinner or made to sin; he is a sinner because he is a transgressor of law (1 John 3:4). But it is possible for him to live in obedience to God's law and overcome temptation. "There hath no temptation taken you but such as is common to man: but God is faithful, who will not suffer you to be tempted above that ye are able; but will with the temptation also make a way to escape, that ye may be able to bear it" (1 Cor. 10:13).
Man can live in harmony with God's will. He is so commanded: "Only let your conversation (citizenship or manner of living) be as it becometh the gospel of Christ" (Phil. 1:27). Sin in the life of a Christian is not the norm but the exception: "if any man sin, we have an advocate with the Father, Jesus Christ the righteous" (1 John 2:1). In becoming a Christian the believer was required to repent and be baptized into Christ for a remission of sins and thereby become dead to sin (Acts 2:38, Rom. 6:2-7). As a Christian he is to keep the commandments of God, but if he sins forgiveness may be obtained through Christ as he repents and prays (Acts 8:22, James 5:16).
If sin is inevitable, then man could not be responsible. Responsibility is response to ability, and without ability to live sinless he could not respond, hence no responsibility. But man is responsible and will be judged by all that he does in the body (2 Cor. 5:10).
In conclusion, John states a fact that all have sinned and can sin (1 John 2:3-6). He writes in condemnation of the theory that once a child of God he can no more sin, that he is released from responsibility to law, and therefore is eternally secure. But the child of God can sin, but he cannot sin with impunity (1 John 3: 3-10). And so he must bring his body into subjection (1 Cor. 9:27) and crucify its desire for unlawful gratification (Col. 3:5-10). He can overcome sin.
Bible Answers, Vol. I, pp. 96-98