Shorter Catechism Q. 84. What doth every sin deserve? A. Every sin deserveth God’s wrath and curse, both in this life, and that which is to come.
Commentary: Although some sins are worse than others (WSC 83), every sin is worthy of “God’s wrath and curse” now and forevermore. Hence, the smallest, slightest and littlest sin deserves to be punished with “the miseries of this life…death itself and…the pains of hell for ever (WSC 19).”
Paul, alluding to various sections in Deuteronomy (but esp. Deut. 27:26), says that everyone who does not abide by all things written in the Book of the Law is cursed (Gal. 3:10). In other words, a person comes under judgment for the slightest infraction of God’s law. Or as James says, “for whoever keeps the whole law but fails in one point has become guilty of all of it (James 2:10).”
It might seem odd to say that the smallest sin, just like the most heinous sin, deserves eternal damnation. We need to remember, however, that sin is not a transgression of an abstract, impersonal code of conduct, or of social conventions, or of man-made rules. Sin, all sin, “is any want of conformity unto, or transgression of the law of God (WSC 14).” To sin is to disobey God and to reject his rightful authority over us. WLC 152 observes that every sin is “against the sovereignty, goodness, and holiness of God, and against his righteous law.” Indeed, it is to exchange the truth for a lie and to worship the creature instead of the Creator, who is blessed forever! (Rom. 1:25). The least sin is evil, and the fact that God will justly punish it with hell is proof of how evil it is.
While every sin deserves God’s wrath and curse, not every sin deserves the same degree of God’s wrath and curse. God will judge people according to what they have been given and according to what they have done. Since some have been given more than others and not all sins are equally heinous, it follows that the punishments will not be same (see Luke 12:42-48). The Judgment will be more tolerable for some than for others (Matt. 11:23).