What does Psalm 51:16 mean?
David knew the importance of offering sacrifices according to the prescribed pattern given in Scripture. He realized it is worthless to offer sacrifices while the heart is in rebellion against God. The blood of bulls and goats could never wash away the stain sin had left on David's heart (Hebrews 10:4).He also knew the Law made no provision for forgiveness of adultery and murder in the sacrificial system. Both transgressions required the death penalty. The Pharisees and scribes in Jesus' day adhered to the Law and the tradition of the elders, but their hearts were not right with God. Jesus called them hypocrites and quoted Isaiah 29:13: "This people honors me with their lips, but their heart is far from me; in vain do they worship me" (Matthew 15:7–9).
Today, some believers try to erase their guilt over sins by increasing their offerings, or helping in the nursery, or cleaning the church, or observing optional traditions such as Lent, or a number of other good works. But these "sacrifices" can never substitute for a heart that loves and obeys the Lord. Nor can those efforts outweigh the offense our sin causes to a perfectly good and holy God.