The short answer to the question is, “No.” There is no sin that is beyond God’s ability to forgive.
One of the most frequently quoted verses in the Bible tells us, “For God so loved the world He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life” (John 3:16). “Whoever” means whoever. There is no one or no sin beyond God’s ability to forgive.
Matthew 12:31–32, however, has caused some confusion: “Therefore I say to you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven men. Anyone who speaks a word against the Son of Man, it will be forgiven him; but whoever speaks against the Holy Spirit, it will not be forgiven him, either in this age or in the age to come.”
Scripture must always be examined in context. The miracles Christ performed were designed to prove He was who He claimed to be—the Son of God—and cause people to come to faith in Him.
Christ had just finished healing one who was demon possessed, blind, and mute. But instead of recognizing Him as the Son of God, the Pharisees insisted, “This fellow does not cast out demons except by Beelzebub, the ruler of the demons” (v. 24).
Christ showed them the foolishness of their unbelief: “If Satan casts out Satan, he is divided against himself. How then will his kingdom stand? And if I cast out demons by Beelzebub, by whom do your sons cast them out? Therefore they shall be your judges. But if I cast out demons by the Spirit of God, surely the kingdom of God has come upon you” (vv. 26–28).
After that, Christ brought up their blasphemy against the Spirit, which some refer to as the “unpardonable sin”—attributing to Satan the works done by the Holy Spirit. He was in essence saying, “I have nothing else to show you. If you do not accept these miracles and recognize me for who I am, then your sin cannot be forgiven you.”
Since Christ is not here in our midst as He was in that day, the unpardonable sin He spoke of cannot be committed. There is no unpardonable sin.
At the same time, if a person goes to his grave having never trusted Christ, there is no going back from eternal separation from God. But the problem is not that his sin of not trusting Christ could not have been forgiven; the problem was he never came to Christ.
There is no sinner who is beyond God’s ability to pardon, and no sin He cannot forgive. Hence the one who goes to his grave without having trusted Christ, suffers eternity apart from God because of his rejection of Christ, not Christ’s rejection of him.