“Isaiah issues a clarion call in the name of the Lord: ‘Let the wicked forsake his way, and the unrighteous man his thoughts.’ He is not calling upon His people to become irrational when He tells them to ‘forsake their thoughts.’ He is commanding them to cease from pursuing Him according to their perceptions of what is or is not pleasing in His sight.
This is followed by a contrast between the thoughts of God and the thoughts of man, in which it is declared that the Lord's thoughts are infinitely higher than man's. The plain fact of the matter is that man is incapable of conceiving through his own understanding what is pleasing to the Lord. The basis of all false worship is the prideful presumption that man is able to contrive means of approaching God with which He will be pleased.
Man finds great satisfaction in the inventions that he brings to the Lord's house: ‘They have chosen their own ways, and their soul delights in their abominations’ (66:3). Yet God proclaims his verdict: ‘They did evil before My eyes, and chose that in which I do not delight’ (66: 4). All of this is predicated upon God's transcendence: ‘Heaven is My throne, and earth is my footstool. Where is the house that you will build for Me?’ (66:1). Therefore Calvin says, ‘if men diligently considered what is the nature of God, they would not contrive foreign and new modes of worship for him, or measure him by themselves.’
God delights not in our proud creativity, but in our humble obedience before Him.” (Comin, 222-223)
True worship is commonly portrayed as an offense to God (Isaiah 36:1- 37:7)
“The people of Judah were facing God's judgment because of their sins, first toward God in corrupting His worship, and then toward men in corrupting justice. The solution to their problem was repentance, beginning with the reformation of worship. Toward this end. God had raised up Hezekiah, who instituted sweeping reforms of worship throughout the land, banishing all man-made inventions and restoring God's pure ordinances to their proper place. It was not long, however, before these grand reforms were called into question, and the seeds of doubt were sown in the hearts of the people.
The king of Assyria, who designed to overthrow Jerusalem, sent his representative Rabshakeh to shake the confidence of the people. Part of his strategy involved convincing them that God would not deliver them from the hand of Sennacherib the king. He suggested to the people that God was offended by Hezekiah’s reforms, because many glorious means of worship had been taken away by the overzealous reformer.
It is a common strategy of the enemy to undo any progress toward restoring the purity of God's worship by encouraging the notion that God was actually pleased by our former inventions and is offended by our forsaking of them. When men are convinced by this deception, and return to their will- worship, the enemy gains a great victory, for God is then genuinely offended and His wrath is kindled against His wayward people.
We must steadfastly resist the suggestions of Satan that our forsaking of human inventions deprives God of honor. Clarity on the matter is found, as Hezekiah discovered, by resorting to the house of the Lord. He will confirm to us, as we seek His face, that it is true worship from a contrite heart that He desires.” (Comin, 221-222)
“The worship of the people of Judah in the days of Isaiah had become an empty sham. Little by little, they had laid aside the commandments of God in favor of the commandments of men. As a judgment against them for their wicked presumption, the Lord gave them up to blindness.
This spiritual blindness to the plain truth of God's Word was particularly evident in the prophets, upon whom was poured out ‘a spirit of deep sleep.’ As for the people, the Bible had become to them ‘a sealed book.’ Its teachings were unintelligible to them, as if they were illiterate.
It is not difficult to see how these things apply to the Church today. When God's commands are displaced by the doctrines and commandments of men, the teachers are given over to spiritual blindness and Biblical illiteracy becomes the defining characteristic of the people. People continue to ‘draw near to God,’ but they only render lip-service to Him, since their hearts are not instructed by a love for His precepts. They prefer to follow the dictates of their own wisdom and their worship becomes a vain show.
Matthew Henry writes: ‘They do not make the word of God the rule of their worship, nor his will their reason. They worshipped the God of Israel, not according to his appointment, but their own inventions, the directions of their false prophets or their idolatrous kings, or the usages of the nations that were around them. The tradition of the elders was of more value and validity with them than the laws which move God commanded Moses.’
Jesus clearly applied this passage to the superstitious practices of the Pharisees, who elevated human traditions above God's commands in their worship. Paul also alludes to it in Colossians 2:22, by which it is clear that this principle applies with equal force to New Covenant worship. The commandments of men are not to be the rule of worship. When they become so, God gives the Church over to a spirit of stupor, and the people fall into doctrinal ignorance.” (Comin, 220-221)