How do we know the New Covenant is necessary?

The necessity of the New Covenant arises from the failure of the old covenant, as seen in Jeremiah 11, where God laments the disobedience of His people. The old covenant required perfect obedience, which humanity, being sinful, could not fulfill. Romans 8:3 indicates that 'what the law could not do, in that it was weak through the flesh,' reveals that humanity's sinful nature rendered them incapable of upholding God's commandments. Therefore, a new covenant, which Christ initiated with His blood, became essential for redemption and for establishing a true relationship with God.