How do we know that only Jesus can give us a pure heart?

The scriptures assert that it is only through Jesus Christ that believers receive a pure heart. 1 John 1:7 states, 'The blood of Jesus cleanses us from all sin,' underscoring the necessity of His sacrificial death for our spiritual cleansing. In the Old Testament, rituals involving blood sacrificial rites served as types foreshadowing the ultimate sacrifice of Christ. The washing away of sin through His blood purifies our conscience, making it evident that true purity is contingent solely upon faith in Him, rather than any works we might perform.