Sin is disobeying God’s will by acts of commission or omission, including activity of the mind. The payment for sin is death (Rom. 6:23), and either we must pay that penalty, or a substitute who is without sin must pay it for us. Jesus Christ was without sin (1 Peter 2:22-23). He willingly, then, “himself bore our sins in his body on the tree so that we might die to sins and live for righteousness; by his wounds you have been healed” (v. 24). The Father freely gave His Son for this purpose (Rom. 8:32), and Jesus affirmed that the goal of His ministry was to seek and to save the lost (Luke 19:10). On the cross that goal was “finished,” (John 19:30). Not only was sin paid, but Christ became our sin, so that we could have His righteousness--“God made him who had no sin to be sin for us, so that in him we might become the righteousness of God.” (2 Cor. 5:21). Paul wrote elsewhere, “at just the right time, when we were still powerless, Christ died for the ungodly” (Rom. 5:6). God provided the means to pay for our sin when we were powerless to do so. Otherwise each day we live we would heap higher the debt we owe to God, due to our sin.
God does not demand double payment for sin. If we accept Christ’s payment for our sins, by faith, then we ourselves will not have to pay for that sin. If we do not accept that payment, we attempt to establish our own righteousness before God, just as unbelieving Jews did in New Testament days—Rom. 10:3 “Since they did not know the righteousness that comes from God and sought to establish their own, they did not submit to God's righteousness. 4 Christ is the end of the law so that there may be righteousness for everyone who believes.” Righteousness—or being right before God—is through faith, not through our righteous acts (Rom. 10:9-10)1. We’re justified, or made right with God, as a gift of His mercy and grace, through faith, which faith Eph. 2:8-9 says even comes from God, not from ourselves. Paul says that our faith gains access to the grace of God “in which we now stand.” (Rom. 5:2). Further. “Everyone who calls on the name of the Lord will be saved.” (Rom. 10:13). “Anyone who trusts in him will never be put to shame.” (Rom. 10:11). So Christians don’t stand condemned, but stand in grace and Sonship.
Not only do we have access to God’s grace, but the blood of Christ “justifies” us, or makes us right with God, saving us from His wrath (Rom. 5:9). Through Christ, we sinners are reconciled to God, and He even becomes our Father (Rom. 5:10-11). There is now nothing between the Father and His child, because anything odious to God has been totally paid for by Christ.
When a person does not have an assurance of salvation the problem is usually because some degree of trust is placed upon personal righteousness. Once any degree of faith is placed upon our good deeds, instead of total trust upon what Christ accomplished on the cross, doubt enters. This is so because we cannot rely completely upon ourselves for any degree of righteousness, and knowing our inconsistency, we are forced to doubt our salvation. But salvation is not Christ’s death for our sin, plus our personal righteousness. When our salvation is based totally upon what Christ did, and not at all upon our own “righteousness,” we can be completely sure of our salvation, because we can be completely sure of Christ. Our deeds indicate our saving faith, but our saving faith, not our deeds, save us (James 2:17-18).
We may think that Christ’s sacrifice paid only for sins of the past and possibly the present, not of the future. Thus, we start by faith, but then go on in the flesh (Gal. 3:3), as if somehow we can now live life acceptably, despite never having been able to do so in the past. If Christ’s death on the cross didn’t pay for future (to our conversion) sins, not one person would go to heaven. God already tells us through John that we will sin, even though we do not have to practice (be enslaved by) sin (2 Cor. 5:21).
The tendency to sin is still present in the born-again believer. This is confirmed by John at 1 John 1:8, “If we claim to be without sin, we deceive ourselves and the truth is not in us.” (NIV). This was written to John’s “children” in the faith (1 John 2:1).
Comparing with Rom. 6:6-7 (“For we know that our old self was crucified with him so that the body of sin might be done away with, that we should no longer be slaves to sin-- because anyone who has died has been freed from sin”) we understand that we’re no longer a “slave” to sin—sin is no longer our master (cf. 2 Peter 2:19). This conforms to 1 Cor. 10:13, which promises a way of escape from every temptation known to us. Further, God within us makes us stronger than those tempting us from outside (1 John 4:4 “You, dear children, are from God and have overcome them, because the one who is in you is greater than the one who is in the world.”)
God’s provision for sin in the Christian is most clearly stated at 1 John 1:9, “If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness.” I doubt that anyone knows the full extent of sins committed against God, so God purifies us from ALL unrighteousness if we are trying to be honest with Him in identifying realized sins. Jesus suggested that we pray a kind of blanket prayer for forgiveness (“forgive us our sins”—Luke 11:4).
God has also provided “precious promises” such as 1 Cor. 10:13 which provide “everything we need …for godliness.” (2 Peter 1:3). The Bible, as a means of grace, shows us the light in which to walk (1 John 1:7) and enables us to grow strong (1 Peter 2:2).
Obviously we aren’t to excuse, or make arrangements to sin (Rom. 6:6; 13:14). "Everyone who confesses the name of the Lord must turn away from wickedness." (2 Tim. 2:19). We are to make “every effort” (Luke 13:24; 2 Peter 1:5) to please God. This is the purpose of putting on the full armor of God (Eph. 6). The result of being filled with the spirit is that we won’t make provision for sin (Eph. 5:18). As we walk in the Spirit, keeping in step with the Spirit (Gal. 5:25), and being filled with the Spirit, we will avoid sin, even if not perfectly.
There are differences in the seriousness of sins. Sins against the body are more serious than those not against the body, apparently (1 Cor. 6:18). Paul considered the sin of an immoral man in the Corinthian church of such gravity that he turned the man’s body over to Satan for the destruction of his body (1 Cor. 5:5) that his spirit might be saved. Luke 12:48 indicates that sins committed in ignorance are less blameworthy than those done with knowledge. Sins turning children from God are extremely grave (Matt. 18:6).
All these sins can be forgiven. “I tell you the truth, all the sins and blasphemies of men will be forgiven them” (Mark 3:28). Peter was forgiven for denying Christ at His point of greatest human need. Paul was forgiven of persecuting Christian, possibly to the death. But the only unforgivable sin is that against the Holy Spirit (Mark 3:29; Luke 12:10). While there are degrees of sin and punishment, there aren’t in scripture a whole category of “mortal” sins versus “venial” (smaller) sins. There is just one unforgivable sin. The Spirit testifies of Christ, and particularly of the sin of not believing in Christ (John 16:8-9). If we continue to reject the Spirit’s leading to put our faith in Christ, and reject it even to the point of death, there is no other provision for our sin, and thus our sin becomes unforgivable. Upon death we face judgment (Heb. 9:27), not another chance to receive Christ (John 1:12). I once thought that I committed this sin and was in great agony of spirit. But I came to understand, as someone has written, that those most concerned about this sin are those least likely to have committed it. Those who do not care about pleasing God are those most likely to commit it.
God encourages us to “draw near” to Him, through the access gained by the sacrifice of Christ (Hebrews 10:19-22), with sincerity and confidence. When we return to God, it must be whole-hearted, as far as possible with us. Four times in the Bible we are encouraged to draw near to God (Heb. 10:22; Zechariah 1:3; Malachi 3:7 and James 4:8). Each time involves turning from known sin, indicating sincerity. Zechariah says, “Turn from your evil ways” (1:4). Malachi says to stop robbing God by our stinginess (Mal. 3:8). James says to “Wash your hands, you sinners, and purify your hearts, you double-minded…Humble yourselves before the Lord and He will lift you up” (James 4:8,10). Three times God tells us that if we draw near to Him, He will draw near to us. That is a promise, but the first step is ours.
Hebrews adds the warning that “If we deliberately keep on sinning after we have received the knowledge of the truth, no sacrifice for sins is left” (Heb. 10:26). If we despise the blood of Christ and His sacrifice and think it provides a license to sin and be forgiven again, we’re mistaken. God will judge His people. “It is a dreadful thing to fall into the hands of the living God.” (Heb. 10:30-31). This is not meant to disturb those sincerely attempting to follow Christ, but who still sin—Christians do sin. But this is meant to disturb those who think Christ is just “fire insurance” against Hell and who think that because God is forgiving that they can live like the Devil, sinning with impunity without consequences. Our stubborn sinning can lead to God no longer hearing our prayers (Isaiah 59:1-18) and standing aloof from our despair. It can lead to God’s severe judgment (Jeremiah 15:1-10). But He will come to those who repent (Isaiah 59:19-20), and God always saves the faithful minority, as well as the sincere of heart.
In conclusion, if we are reconciled to God, if we have become children of God (John 1:12), if Christ has become our personal righteousness and if we stand in the grace of God, all of which are the privileges of a Christian, then God may be said to be “for us.” If the only thing between us and God—sin—is totally paid for, then we are no longer enemies of God, and God is for us. Now if God is for us, “Who will bring any charge against those whom God has chosen? It is God who justifies. Who is he that condemns? Christ Jesus, who died—more than that, who was raised to life—is at the right hand of God and is also interceding for us. Who shall separate us from the love of Christ?...For I am convinced that neither death nor life, neither angels nor demons, neither the present nor the future, nor any powers, neither height nor depth, nor anything else in all creation, will be able to separate us from the love of God that is in Christ Jesus our Lord.” (Rom. 8:33-34, 38-39). Some think that we can separate ourselves from the love of God. But we aren’t stronger than angels or demons and cannot separate ourselves from God’s love in Christ Jesus.
1 Eph. 2:8-9; Titus 3:5-7—“But when the kindness and love of God our Savior appeared, 5 he saved us, not because of righteous things we had done, but because of his mercy. He saved us through the washing of rebirth and renewal by the Holy Spirit, 6 whom he poured out on us generously through Jesus Christ our Savior, 7 so that, having been justified by his grace, we might become heirs having the hope of eternal life.”