Matthew 12:45 Then goeth he, and taketh with himself seven other spirits more wicked than himself, and they enter in and dwell there: and the last state of that man is worse than the first. Even so shall it be also unto this wicked generation.
[Patriarchs & Prophets pp 635] No stronger evidence can be given of Satan's delusive power than that many who are thus led by him deceive themselves with the belief that they are in the service of God. When Korah, Dathan, and Abiram rebelled against the authority of Moses, they thought they were opposing only a human leader, a man like themselves; and they came to believe that they were verily doing God service. But in rejecting God's chosen instrument they rejected Christ; they insulted the Spirit of God.
So, in the days of Christ, the Jewish scribes and elders, who professed great zeal for the honor of God, crucified His Son. The same spirit still exists in the hearts of those who set themselves to follow their own will in opposition to the will of God. Saul had had the most ample proof that Samuel was divinely inspired. His venturing to disregard the command of God through the prophet was against the dictates of reason and sound judgment. His fatal presumption must be attributed to satanic sorcery.
Saul had manifested great zeal in suppressing idolatry and witchcraft; yet in his disobedience to the divine command he had been actuated by the same spirit of opposition to God and had been as really inspired by Satan as are those who practice sorcery; and when reproved, he had added stubbornness to rebellion. He could have offered no greater insult to the Spirit of God had he openly united with idolaters.
Matthew 12:32 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.
May The Lord add His blessing to the study of His word. God bless!