Isaiah 66:2-3 For all those things hath mine hand made, and all those things have been, saith the LORD: but to this man will I look, even to him that is poor and of a contrite spirit, and trembleth at my word. He that killeth an ox is as if he slew a man; he that sacrificeth a lamb, as if he cut off a dog's neck; he that offereth an oblation, as if he offered swine's blood; he that burneth incense, as if he blessed an idol. Yea, they have chosen their own ways, and their soul delighteth in their abominations.When reading these verses in context of the entire chapter, you see that the people approached sacrifices as rituals; the sacrifice had lost meaning and they were just doing it because it is what they were supposed to do.
God desires our hearts. His concern is not with who gives the most or who gives the best speeches, or who knows the most scripture. He wants our hearts! If we give what little we have out of our thanks for Him, He is happy. If we speak His Word to others, He is happy. If we tremble at hearing His word, then He is happy.
What does it mean if we stand in church and open our mouths to sing if we don't have a spirit of praise? What does it mean if we put something in the offering, but not willingly or with respect? God sees our complacency as an abomination. Traditions and rituals can become vain repetitions if our hearts are not in the actions.
Ecclesiastes 1:2 Vanity of vanities, saith the Preacher, vanity of vanities; all is vanity.