Are Some Sins Worse Than Others?
John Frame answers:
Are some sins worse than others? Any sin deserves eternal condemnation. In that sense, all sins are equal before God (Gen. 2:17, Deut. 27:26, Ezek. 18:4, 33:8, Rom. 5:16, 6:23, Gal. 3:10, Jas. 2:10-11). But some sins have more harmful consequences than others in this life, and some even offend God more deeply than others. So Scripture distinguishes greater and lesser sins (Ezek. 8:6, 13, 15, Matt. 5:19, 23:23, John 19:11), unwitting and high-handed sins (Lev. 4:2, 13, 22, 5:17, Num. 15:27-30), weightier and less weighty sins. Some sins and errors deserve excommunication, as the incestuous man in Corinth (1 Cor. 6); others do not, as the vegetarians in Rome (Rom. 14). James (3:1, cf. Luke 12:48) says that teachers will be judged with greater strictness. The sins of teachers are often worse than the sins of others, because teachers can lead others astray by their errors and their poor example. Remember that as you plan to minister in the church. To whom much is given, much is required.
One sin is so bad that it is called “unpardonable” (Matt. 12:31-32; cf. Heb. 6:4-6, 10:26-27, 1 John 5:16-17). It is difficult to understand precisely what this means, but I think the best definition of the unpardonable sin is Wayne Grudem’s: “a malicious, willful rejection and slander against the Holy Spirit’s work attesting to Christ, and attributing that work to Satan.” This does not refer to a one-time thoughtless remark, but a general pattern of opposition to the Spirit’s work. At some point, the enemies of Christ reach a point in their unbelief where they are so hardened they can no longer repent. I cannot define precisely what that point is in any specific case. I will say though that if your conscience is troubled by the thought that you might have committed the unpardonable sin, you haven’t. People who have committed that sin have hardened consciences, and they are no longer troubled by such concerns.
-John Frame, Salvation Belongs to the Lord