What does the Bible say about religious practices and God's acceptance?

In Isaiah 58, God reveals that mere religious practices, such as fasting and sacrifices, are detestable when offered without the recognition of Christ as the ultimate sin offering. God desires heartfelt worship that acknowledges our wretchedness and Christ's righteousness. This is underscored in Hebrews 10, where we see that the blood of animals cannot take away sin; only the blood of Christ is sufficient for redemption. Therefore, any religious act done with the intent of establishing one's own righteousness will not gain favor with God.