Galatians 3:15-18 NIV

[15] Brothers and sisters, let me take an example from everyday life. Just as no one can set aside or add to a human covenant that has been duly established, so it is in this case. [16] The promises were spoken to Abraham and to his seed. Scripture does not say “and to seeds,” meaning many people, but “and to your seed,” meaning one person, who is Christ. [17] What I mean is this: The law, introduced 430 years later, does not set aside the covenant previously established by God and thus do away with the promise. [18] For if the inheritance depends on the law, then it no longer depends on the promise; but God in his grace gave it to Abraham through a promise.