What would you think of the man who constantly brings flowers and gifts home to a wife, while he has a mistress on the side? One day he is praising her for her beauty and devotion and the next night he is having a secret rendezvous in another city hotel. Would that make you mad? Would you want to do something about it?
The Lord God through the mouth of the prophet Isaiah is calling His people out for something much worse. He says that they are just going through the motions in their worship. Every Sunday in Christian gatherings there are those who lift up heartfelt and genuine worship to God. Yet, in that same gathering there are those who sing the same songs, listen to the same message and walk the same halls whose hearts and daily lives are far away from God.
Like the wheat and chaff that Jesus speaks of in Matthew 13 you can't tell the difference sometimes, but eventually (in the end) tares show who they really are. Jesus says,
'Allow both to grow together until the harvest; and in the time of the harvest I will say to the reapers, "First gather up the tares and bind them in bundles to burn them up; but gather the wheat into my barn."'" Matthew 13:30 (NASB)
In Matthew 3:12 Jesus says, "His winnowing fork is in His hand, and He will thoroughly clear His threshing floor; and He will gather His wheat into the barn, but He will burn up the chaff with unquenchable fire."
He calls their worship a farce. It makes it no farther than the ceiling. It is in no way the "fragrant aroma" that true worship is meant to be and that God deserves.
He promises to "deal wondrously marvelous" toward them. What in the world does that mean? Well it probably doesn't mean what we think it means. Just as Solomon ask God for wisdom to know how to go out and come in, God will remove that wisdom and discernment.
To be far away from God is to be like that hot ember removed from the fire which eventually grows cold. He will take away their wisdom and hide their discernment.
James 4:8 (NASB)
8 Draw near to God and He will draw near to you. Cleanse your hands, you sinners; and purify your hearts, you double-minded.
25 Therefore He is able also to save forever those who draw near to God through Him, since He always lives to make intercession for them.