(Leviticus 10:1) And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the LORD, which he commanded them not.
The mere appearance of our offerings and righteous acts make no difference with God. Nadab and Abihu had the form of performing a good thing before the Lord yet it was an act of disobedience. They offered strange fire because it was their own will to offer it not the will and commandment of God.
Just because something looks holy doesn’t mean it is holy. Even Cain offered a sacrifice unto the Lord yet in his heart it was nothing more than good works from his own hands. Solemn music, white robes, reverent faces and even a large Bible do not create holiness before God.
Our offerings before God become holy when they are offered in the method prescribed by God in His Word and out of a heart that is already made righteous by the righteousness of Christ. We cannot obtain righteousness through our own offerings or else we are just committing the same sin as Cain in lifting up our own good works. We cannot demonstrate holiness by our own invented external acts of ceremonial procession or else we are just committing the same sin as Nadab and Abihu. Paul tells us in Romans 12 that we are the living sacrifice laid down as a result of a mind that is renewed by the Word of God and a life transformed by His indwelling presence. This is what makes our offering acceptable. We cannot obtain grace nor can we maintain grace through our own works. There are many people eternally separated from God who lived a very religious life.
(Romans 11:6) And if by grace, then is it no more of works: otherwise grace is no more grace. But if it be of works, then is it no more grace: otherwise work is no more work.
Renewed Thought: Don’t be fooled into thinking that religious and ceremonial acts make us holy. Any offering that God accepts from us must be a result of His holiness already working in us and through us.