The sacrifice of the wicked is an abomination to Adonai, but the prayer of the upright pleases him.
Proverbs 15:8 TLV

God demanded sacrifice from his people, but he required that they come with a penitent and humble heart. Sacrifices brought in a spirit of pride, entitlement, and manipulation are worse than no sacrifice at all.

The simple prayer of the upright is of more value to God than all the sacrifices of the wicked. This is because the purpose of sacrifice is to restore and enhance the worshiper's relationship to him. If a man's heart is unwilling to be restored to God, then sacrifice is of no more value to him than turning the knob of a locked door. Repentance is the key that unlocks the door of atonement.