Is there any sin God cannot forgive?
Scripture teaches that God can forgive any sin, even the vilest, except one: unbelief. The only sin God cannot forgive is refusing to believe the gospel—that Christ died for them, paid their sin debt, and rose from the dead in power. Persistent unbelief seals a person's doom.
Les explains that Israel's sin with the golden calf, though vile, was forgivable. Their real problem was unbelief—they could not believe what God said. He points to the passage where they could not enter His rest because of unbelief. Les asks if anything has changed and answers no. God can forgive to the uttermost any sin, the vilest, except unbelief. When people refuse to believe that Christ died for them, paid their sin debt, and rose from the dead in power, that is the one sin God cannot forgive. If a person refuses to believe that gospel, his doom is sealed.