28"Truly I say to you, all sins shall be forgiven the sons of men, and whatever blasphemies they utter; 29but whoever blasphemes against the Holy Spirit never has forgiveness, but is guilty of an eternal sin"— 30because they were saying, "He has an unclean spirit."
Mar_3:28 "Truly" This is literally "amen." Jesus' initial use of "truly" is unique. It usually precedes a significant statement.
▣ "all sins shall be forgiven the sons of men, and whatever blasphemies they utter" This showed the scope of God's grace in Christ. The phrase "the sons of men" is the normal Semitic idiom referring to human beings (cf. Psa_8:4; Eze_2:1).
Mar_3:29 "but whoever blasphemes against the Holy Spirit" This must be understood in its pre-Pentecostal historical setting. It was used in the sense of God's truth being rejected. The teaching of this verse has commonly been called "the unpardonable sin." It must be interpreted in light of the following criteria:
1. the distinction in the OT between "intentional" and "unintentional sins," (cf. Num_15:27-31)
2. the unbelief of Jesus' own family contrasted with the unbelief of the Pharisees in this context
3. the statements of forgiveness in Mar_3:28
4. the differences between the Gospel parallels, particularly the change of "son of man," (cf. Mat_12:32; Luk_12:10) to "sons of men," (cf. Mat_12:31; Mar_3:28).
In light of the above, this sin is committed by those who, in the presence of great light and understanding, still reject Jesus as God's means of revelation and salvation. They turn the light of the gospel into the darkness of Satan (cf. Mar_3:30). They reject the Spirit's drawing and conviction (cf. Joh_6:44; Joh_6:65). The unpardonable sin is not a rejection by God because of some single act or word, but the continual, ongoing rejection of God in Christ by willful unbelief (i.e., the scribes and Pharisees).
This sin can only be committed by those who have been exposed to the gospel. Those who have heard the message about Jesus clearly are the most responsible for its rejection. This is especially true of modern cultures that have continual access to the gospel, but reject Jesus (i.e., America, western culture).
For the Holy Spirit as the third person of the Trinity see Special Topic following.