It is not true that all sins are equally sinful. This becomes apparent when we remember what Jesus said about blaspheming the Holy Spirit.
Every sin and blasphemy will be forgiven people, but the blasphemy against the Spirit will not be forgiven. And whoever speaks a word against the Son of Man will be forgiven, but whoever speaks against the Holy Spirit will not be forgiven, either in this age or in the age to come (Matt 12:31-32)The very fact that there is a sin that God will not forgive shows that not all sins are equally sinful. Blasphemy against the Son of Man (against Jesus), God will forgive—when there is due repentance. Blasphemy against the Holy Spirit…no.
Perhaps this is what the apostle John has in mind when he says,
If anyone sees his brother committing a sin not leading to death, he shall ask, and God will give him life—to those who commit sins that do not lead to death. There is a sin that leads to death; I do not say that one should pray for that. All wrongdoing is sin, but there is sin that does not lead to death (1 Jn. 5:16-17)There are many differences of opinion as to what exactly John means by “sins leading to death”, but by the very circumstance that he categorizes sins as those leading to death, and those not leading to death, shows that not all sins are equally sinful.
We should also consider the fact that Jesus spoke of some matters of the law as being “weightier” (of more importance) than others.
Woe to you, scribes and Pharisees, hypocrites! For you tithe mint and dill and cumin, and have neglected the weightier matters of the law: justice and mercy and faithfulness. These you ought to have done, without neglecting the others (Matt. 23:23)In the law of Moses we see that God has assigned different penalties to different crimes, showing that he regards some crimes (sins) to be more serious than others.
The very fact that there are varying degrees of punishment also shows that there are varying degrees of sinfulness. Remember that Jesus said it would be “more tolerable” for the Gentile cities of Tyre and Sidon in the day of judgment than for the Jewish cities of Chorazin and Bethsaida, and more tolerable for Sodom than for Capernaum (Matt. 11:20-24). And the reason was this: these Jewish cities sinned against greater knowledge. They had Jesus in the midst. They heard his teaching and saw his miracles, and still they refused to repent. Their guilt was far greater than the guilt of these Gentile cities and so their punishment would be greater.
When we consider the nature of various sins, we can see that some sins are inherently more harmful and destructive, and therefore more serious than others. For instance, who can doubt that a violation of the sixth commandment is more harmful than a violation of the tenth? To commit murder is more serious and destructive than to covet your neighbor’s donkey. And a murderer will be more severely punished by God than a covetous man.
It is true that all sins are condemnable, and will be condemned by God. But it is not true that all sins are equally sinful.
We should point out, however, that as all sins are condemnable, they all must be atoned for if one is to be forgiven and find acceptance with God. To say that some sins are more serious than others is not to say that if one is only guilty of lesser sins he has no need of the grace and mercy of Christ. Every sinner, whether a squeaky clean one (by human standards) or a grossly wicked one stand in need of the salvation that only Christ can offer.