Obviously, all sin is serious, since any sin is a sin for which Jesus had to die. And the death of Jesus doesn’t make sins committed post Calvary less serious. If anything, it makes it more serious. Sin in a Christian’s life is a very serious matter indeed, especially if we are talking about sins of commission, but even sins of omission can be very serious. For example, if you fail to love your neighbor as your self, if you fail to love your enemies, that’s a very serious matter indeed. In the former case, it amounts to a violation of the Great Commandment reaffirmed by Jesus. In the latter case, it involves a direct violation of a commandment of Jesus to his disciples in the Sermon on the Mount. Not good either way.
The basic principle Christians need to keep in mind is that ‘to whom more is given, more is required’. That is, sin becomes more serious, the more one knows and understands the gravity of what one is doing, and how clearly God has prohibited such a thing. According to the OT, judgment begins with the household of God, and there is no reason to think this principle doesn’t apply to the church just as well as to Israel. Indeed, any serious student of the Sermon of the Mount will realize that Jesus is intensifying God’s demands on us. Why is that? Because of course not only to we have the fuller revelation of God’s will through the life and teaching of Jesus, but also because God has given us his Spirit since Pentecost which enables us to better obey God and indeed to avoid willful sin. ‘To whom more is given…. more is required’. Unfortunately, some Christian theologies, like for example the ‘once saved, always saved’ aberration to often lead to an assumption that sin in a Christian’s life is not all that serious a matter. After all, one already has universal amnesty and forgiveness— right? Not quite. Even if this were a good theology (and it’s not), do you really want to explain to Jesus at the eschaton why you took his forgiveness as a license to sin? I don’t think so.
“The acts of the sinful inclination are obvious: sexual immorality, impurity and debauchery; idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions and envy; drunkenness, orgies, and the like. I warn you, as I did before, that those who live like this will not inherit the kingdom of God.” Notice who Paul is warning— namely every single one of the Galatian converts. Notice that he doesn’t say ‘you folks who are elect amongst the congregation don’t need to worry about this’. Now Paul is not talking somebody committing a one time sinful act like those listed. He is talking about a pattern of behavior. Nevertheless, Paul, like the author of Heb. 6 does believe it is possible for a genuine Christian to commit apostasy– whether moral (as here is in mind) or intellectual apostasy. Either way, as the author of Heb. 6, a person who has experienced the Holy Spirit, embraced Christ, etc. etc. and then does this is guilty of crucifying Christ afresh— a horrific sin. It is possible that 1 John 5 is also about this matter when the author talks about a ‘sin unto (spiritual) death’. The Spirit can be quenched or grieved, so don’t go there is the message of the NT. You’re not eternally secure until you are securely in eternity. That’s the facts Jack. So even the devout Christian must guard their heart, and rely on the grace of God to stand each and every day. Whether apostasy is the ‘unforgivable sin’ can be debated, but if there is one such sin, it is likely this one.
In our next post we will discuss what to do with sin in your Christian life.