The defense of Jesus: V. 27. 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.
Over against the slanderous, blasphemous explanation of the Jews, Jesus now places His simple and true explanation. The devil is strong and mighty, indeed, but in Christ he has found more than his match, he has met Him whom he must acknowledge, without question, as his Master. Christ, the Son of God, has entered into the house of the strong one, Satan; He has taken with Him the spoil which fell to His lot at the time of His great victory.
The demons, all the evil angels, had to confess Him and bow before Him as the Son of God; they were obliged to obey, even against their will, for all things have been put under His feet, Eph. 1, 22. By His life, Passion, and death, by His active and passive obedience to His heavenly Father's will Christ has conquered the devil and delivered all men from his power. Thus it is that Christ can now seize the spoils taken from Satan, tear from him his possessions, also those poor people whom he has possessed. This our Lord does even today through the Word, by which the souls of men are delivered from the power of the devil.
A warning against the unforgivable sin: V. 28. Verily I say unto you, All sins shall be forgiven unto the sons of men, and blasphemies wherewith soever they shall blaspheme; v. 29. but he that shall blaspheme against the Holy Ghost hath never forgiveness, but is in danger of eternal damnation: v. 30. because they said, He hath an unclean spirit. With solemn emphasis Jesus gives the Pharisees this warning. Jesus knew that the scribes did not believe their own theory as to His ability to cast out devils. "You are not merely mistaken theorists, you are men in a very perilous moral condition. Beware!" (Expositor's Greek Testament, 1, 362).
God's mercy is as wide as heaven and earth; His forgiveness actually embraces all sins, even the ordinary blasphemies, wherewith so many people continually offend against Him. But there is one great exception, namely, when the blasphemy is directed against the Holy Ghost. This sin is unpardonable, its guilt lasts forever, it has no forgiveness forever. He that commits it is guilty of a transgression whose consequences will last throughout eternity.
This solemn and complete declaration was called forth by the charge of the Jews that Jesus had an unclean spirit. Thus the blasphemy was directed against the Spirit of God that lived in Christ, and hence His warning. If the scribes had been ignorant, or if they had misunderstood the Lord and had been seeking some explanation of His strange power over demons, that would have been a sin against the Son of Man, and therefore pardonable. But they spoke against better knowledge; their charge was a deliberate, malicious blasphemy, and therefore their charge cast mockery upon the Holy Ghost.