D.L. Moody addresses the concept of the unpardonable sin, emphasizing the gravity of blaspheming the Holy Spirit. He explains that while all sins can be forgiven, attributing the works of Jesus to the devil is a serious offense that leads to eternal damnation. Moody clarifies that the unpardonable sin involves a deliberate and malicious rejection of Christ's divine nature and power. He reassures believers that true repentance and faith in Jesus protect them from this sin, as it requires a conscious and willful denial of the truth. Ultimately, Moody encourages listeners to seek the Holy Spirit and remain aligned with Christ to avoid spiritual peril.

Then was brought unto him one possessed with a devil, blind, and dumb: and he healed him, insomuch that the blind and dumb both spake and saw. And all the people were amazed, and said, Is not this the son of David? But when the Pharisees heard it, they said, This fellow doth not cast out devils, but by Beelzebub the prince of the devils. And Jesus knew their thoughts, and said unto them, Every kingdom divided against itself is brought to desolation; and every city or house divided against itself shall not stand: And if Satan cast out Satan, he is divided against himself; how shall then his kingdom stand? And if I by Beelzebub cast out devils, by whom do your children cast them out? therefore they shall be your judges. But if I cast out devils by the Spirit of God, then the kingdom of God is come unto you. Or else how can one enter into a strong man’s house, and spoil his goods, except he first bind the strong man? and then he will spoil his house. He that is not with me is against me; and he that gathereth not with me scattereth abroad. Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men. And whosoever speaketh a word against the Son of man, it shall be forgiven him: but whosoever speaketh against the Holy Ghost, it shall not be forgiven him, neither in this world, neither in the world to come. That is Matthew’s account. Now let us read Mark’s account in chapter 3:21 etc.: "And when His friends heard of it, they went out to lay hold on Him, for they said: He (that is Christ) is beside Himself. And the scribes which came down from Jerusalem said, He hath Beelzebub, and by the prince of the devils casteth He out devils." The word Beelzebub means the Lord of Filth. They charged the Lord Jesus with being possessed not only with an evil spirit, but with a filthy spirit. "And He called them unto Him, and said unto them in parables, How can Satan cast out Satan? And if a kingdom be divided against itself, that kingdom can not stand. And if a house be divided against itself, that house can not stand. And if Satan rise up against himself, and be divided, he can not stand, but hath an end. No man can enter into a strong man’s house, and spoil his goods, except he will first bind the strong man; and then he will spoil his house. Verily I say unto you, all sins shall be forgiven unto the sons of men, and blasphemies wherewith soever they shall blaspheme: but he that shall blaspheme against the Holy Ghost hath never forgiveness, but is in danger of eternal damnation." Now, if it stopped there, we would be left perhaps in darkness, and we would not exactly understand what the sin against the Holy Ghost is; but the next verse of this same chapter of Mark just throws light upon the whole matter, and we need not be in darkness another minute if we really want light; for observe, the verse reads: Because they said, He hath and unclean spirit." Now, I have met a good many atheists and skeptics and deists and infidels, both in this country and abroad, but I never in my life met a man or woman who ever said that Jesus Christ was possessed of an unclean devil. Did you? I don’t think you every met such a person. I have heard men say bitter things against Christ, but I never heard any man stand up and say that he thought Jesus Christ was possessed with the devil, and that he cast out devils by the power of the devil; and I don’t believe any man or woman has any right to say they have committed the unpardonable sin, unless they have maliciously, and wilfully and deliberately said that they believe that Jesus Christ had a devil in Him, and that He was under the power of the devil, and that He cast out devils by the power of the devil. Because you perhaps have heard some one say that there is such a thing as grieving the Spirit of God, and resisting the Spirit of God until he has taken His flight and left you, then you have said, "That is the unpardonable sin."