1 John 1:9 (ESV) says, “If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.” We all sin. We all fall short of perfection. The solution to these sins is taking them to Jesus for forgiveness, but we often feel we don’t deserve forgiveness or that we have been too bad to forgive. This passage is a wonderful promise of forgiveness because it is tied to very important qualities of Jesus. You can be sure of forgiveness, not because Jesus is “nice” or “kind” enough to forgive. Unfortunately, this is how we often imagine it. Niceness and kindness are vague concepts. What is the nice thing to do in every situation or the kind thing to do? Sometimes being kind or nice can actually inflict discomfort—such as to teach an important lesson. This passage does tie forgiveness to Jesus’ character, but not to these vague qualities. Instead it is tied to two of the strongest qualities of our savior. Our forgiveness is tied to Jesus being faithful and just. The first part, Jesus’ faithfulness says Jesus is going to do exactly what he is supposed to do when he is supposed to do it, without reservation, hesitation or failure. This faithfulness can be scary because if the right thing to do was to exact punishment then we would be punished. But the passage isn’t so vague. It says he “is faithful [to] forgive.” This means Jesus will always (another way of saying “faithfully”) forgive. He doesn’t wait for you to feel sorry enough, or for you to do enough penance. Confess and be forgiven. Jesus forgives because that is his role as our savior. God sent him to secure forgiveness and salvation for us, and he is faithful to do the will of the Father, at all times (John 6:39f). There is no danger of Jesus refusing to forgive you because to do so would violate the will of the father and make the son unfaithful—something he can never be.
But there is another quality of Jesus mentioned here and tied to our forgiveness: justice. It says that Jesus “is just [to] forgive us our sins.” Now wait just a minute! Justice is usually to be feared when guilty of sin. It is justice that balances the scales. Justice responds to evil with punishment. When one is harmed justice forces the guilty party to make recompense. When one sins, it is justice that ensures you receive the punishment you deserve. Justice is not usually associated with forgiveness. Actually, forgiveness is the antithesis of justice. If one is forgiven, then justice was not met. If one receives their just reward, then there was no forgiveness. However, through Christ the forgiveness and cleansing of our sins has changed from unjust to just. You see we deserved death for our sins. Justice would have repaid those sins with death (Romans 6:23a) to balance the scales. But the death of Christ balanced them on our behalf and in our place. This death paid for them fully—not just past sins but all sins (past, present, future). Since the sins are already paid for, forgiveness has already been secured (Hebrews 9:26ff). To refuse to forgive would, itself, be unjust. To refuse to forgive would declare the sacrifice of Christ insufficient.
There is a huge difference between justice without Christ and justice with Christ. Before coming to Christ we were responsible to pay for our own sins. Justice demanded payment. However, once we came to Christ he paid it all and justice assures any subsequent sins are forgiven, fully.
Now, some will still demand a price for this forgiveness—a price paid by the sinner. They will point out that this passage says we will be forgiven “if we confess our sins.” It is claimed (wrongly) that one who does not confess (or fails to confess) will then not be forgiven. This is only possible if the confession is what makes the forgiveness just. To claim this would be to claim that the confession is what makes the sacrifice of Christ sufficient to pay the price, and without our confession the sacrifice of Christ would not be enough. Such a claim, in effect, is a claim of needing “Jesus plus” (it requires my actions to complete the work of Christ). This is abominable. But if you know how to look at such statements you will understand that this is not what the author is saying.
He does not say, “If you confess you will be forgiven, but if you do not confess you will not be forgiven.” No. He says, “If you confess you will be forgiven” then justifies this with the qualities of Jesus. So the first part must be taken by itself, since the latter is meant to justify (or explain) the former. Does it mean that we will only be forgiven if we confess? Of course not.
The statement is what is known in logic as a conditional statement. These take the form of “If A then B” (or in propositional logic A→B). Such statements have two parts: a sufficient clause and a necessary clause. In this case “confess” is the sufficient clause, and “will be forgiven” is the necessary clause. To understand these let’s look at the rules for each:
Sufficient Clause: “A sufficient condition for some state of affairs S is a condition that, if satisfied, guarantees that S obtains.”
Necessary Clause: “A necessary condition for some state of affairs S is a condition that must be satisfied in order for S to obtain.”
(Taken from: http://philosophy.wisc.edu/hausman/341/Skill/nec-suf.htm)
You see, logic (and language is really just a logical way of making statements) has rules for such statements. For a conditional statement to be true, the necessary statement must be true if the sufficient clause is true. In the example of A→B, if A is true, then B must be true or the statement is false. In this case, if I confess and Jesus does not forgive then the statement is false. However, the reverse (If I do not confess, I will not be forgiven) is not impled. That would be a very different statement: (A→B)&(~A→~B) which would be the equivalent of A↔B. Such would actually set confession as the equivalent to forgiveness (the two would define each other). It would ultimately be my confession that causes my forgiveness—a heretical idea. And to make confession a necessary for forgiveness, the statement would be “If you are forgiven, then you have confessed.” This is a very different statement—no longer a promise, but a simple declaration.
The statement “If you confess you will be forgiven” is saying that is you confess your sins you can be sure of being forgiven because of whom Jesus is and what he has done. However, it says nothing at all about what happens if you fail to confess or are unaware of sins and unable to confess them. Those are handled by the second statement: Jesus forgives because he is faithful and just to forgive our sins and to cleanse us. We can also rest assured in other promises, such as 1 Thessalonians 5:23f, which says (ESV), “Now may the God of peace himself sanctify you completely, and may your whole spirit and soul and body be kept blameless at the coming of our Lord Jesus Christ. He who calls you is faithful; he will surely do it.” Add to this the promise of Jesus interceding for us forever as High Priest (Hebrews 6:19f). The Spirit will bring sins to your attention for you to confess. This is not because one must confess to be forgiven—the forgiveness is already secured. The Holy Spirit does this so that you can repent of the sin and turn from it. This is part of sanctification and growth, not a requisite of forgiveness or salvation, which were already secured.
Once you have come to Christ, you are never again in danger of unforgiven sins.