There is a difference between the unpardonable sin and a “Sin Leading to Death”, although the two are often confused when dealing with such a heavy topic.
If anyone sees his brother committing a sin not leading to death, he shall ask and God will for him give life to those who commit sin not leading to death. There is a sin leading to death; I do not say that he should make request for this. All unrighteousness is sin, and there is a sin not leading to death.
– 1 John 5.16-17
The book of First John is intense, to say the least, making statements boldly such as:
We know that no one who is born of God sins; but He who was born of God keeps him, and the evil one does not touch him.
– 1 John 5.18
The intention of the book is to bring about obedience. We should strive to live holy lives, live in the light and not the darkness, to be pure from sin. But when we do sin we have an advocate and forgiveness if we repent (2.1). John, the author, wants to affirm the readers that they do have eternal life, that God hears their prayers, and that they are secure. And we can test our salvation by observing our obedience and lives. Thus, when he draws to the close of his book, he affirms the believers that God hears their prayers and that He will answer.
This is the confidence which we have before Him, that, if we ask anything according to His will, He hears us. And if we know that He hears us in whatever we ask, we know that we have the requests which we have asked from Him.
– 1 John 5.14-15
It is in the framework of understanding that whatever we pray within the will of God, it will happen, that John brings up the sin leading to death. Theologians wrestle with this concept and some of those whom I most highly respect believe this to be a sin that will result in physical death – much like with Ananias and Sapphira. They sold their land and gave a portion of the profit to the Church but lied and said that they had given it all. God, for the purpose of maintaining the integrity of His church, killed them on the spot (Acts 5, 1 Cor 5.5, 11.30).
But others argue, I believe more convincingly, that there is not a severity of actual sin that is committed, but rather a distinction between the sinners themselves. John goes on to say that believers live in the power of God, but everyone else under the power of the evil one (V. 19). And this is where the circular reasoning of the “unpardonable sin” is often culminated. Any sin that is enacted and from which is not repented is not forgiven. Jesus died on the cross to pay the penalty for all sinners who believe and repent. If we continue in our sin and do not turn away from it, and live unto God in obedience to Him, our sins are not forgiven. This is true. And any such sin is a sin unto eternal death. The sin that does not lead to death, therefore, would be one from which the offender repents.
And that is why we see the exhortation that we are to pray for our brothers and sisters in Christ when we see them sinning, that God would call them to repentance, restore him to life and keep him safe from the temptation of sin. But when we see one living in rebellion to God, we should not ask that God grant him eternal life, for we know that God will not grant forgiveness and eternal life apart from repentance. To pray such would be against the will of God, and we should not pray that. We should pray, however, that God will lead such a one to repentance.
How then do we know? How do we test the sinner and the sin? The believer is given the Holy Spirit to convict him of sin, righteousness and judgment (John 16.8). When a believer sins, the Holy Spirit will convict him. Sometimes He does so through the body of Christ. This is why Jesus gives us a thorough outline for how we are to handle sin in the Church. If you see someone sinning, you should go to him in private and confront the sin. If he repents, “you have won your brother” (Matt 18.15). Jesus also extends multiple opportunities for the sinner to repent, and if the single witness is unsuccessful he is to take another with him to confront it again. If the sinner will not listen to a group of two or three, then it is to be taken before the entire church, and if he will not listen even then, he is to be removed from the congregation and turned over to the evil one – all for the purpose of being brought to repentance.
This unrepentant sin is the sin leading to death. Thus we know it is not the actual sin that is being evaluated, for David, the “man after God’s own heart” was an adulterer and murderer but is one of the patriarchs of the faith. Moses, the one with whom God spoke daily and to whom God entrusted the Law and leadership of Israel was also a murderer. These sins are not unpardonable. But lying and being unwilling to repent is. Stealing, and not restoring what was taken and repenting is. Harboring anger or bitterness in the heart is. Murder, adultery and divorce are, when un-repented.
Therefore Paul exhorts us,
So then, my beloved, just as you have always obeyed, not as in my presence only, but now much more in my absence, work out your salvation with fear and trembling; for it is God who is at work in you, both to will and to work for His good pleasure.
– Phil 2.12-13
God is working His good pleasure in us. Let us obey, and work out our salvation in fear in trembling while trusting His transformative work in our lives!