Q: What is the "unforgivable sin"? Can believers commit it?
—Andrew James Isaac, St. Thomas, U.S. Virgin Islands

A: "Truly I tell you, people will be forgiven for their sins and whatever blasphemies they utter; but whoever blasphemes against the Holy Spirit can never have forgiveness, but is guilty of an eternal sin" (Mark 3:28–29, NRSV). These words of Jesus, found in Matthew, Mark, and Luke, contrast blasphemies for which one may receive forgiveness with the blasphemy "against the Holy Spirit," for which one never has forgiveness. Since there is no forgiveness for such blasphemy, the person who commits it is guilty of "an eternal sin." Hence, that sin has come to be known as "the unforgivable sin."

In Mark, Jesus' saying regarding the "eternal sin" follows the scribes' charge that Jesus casts out demons by the power of Beelzebul, the prince of demons. They deny Jesus' claim that his power to cast out demons is a manifestation of the Holy Spirit, that is, of the very power of God. In this context, then, Jesus uses blasphemy of the Holy Spirit to mean attributing the work of the Holy Spirit to the power of Satan.

Blasphemy was a serious charge. Leviticus 24:15–16 pronounced, "Anyone who curses God shall bear the sin. One who blasphemes the name of the LORD shall be put to death; the whole congregation shall stone the blasphemer." In response to the scribes' accusations, Jesus in effect says that those who attribute his deeds to the power of Satan have committed a capital offense; they are "guilty of an eternal sin."

But Jesus does not call for death at the hands of the congregation. Instead, we hear a message of grace and of the great scope of forgiveness that is possible with God: "all sins" (a literal rendering of the ...