John Wesley on Galatians 3:21

Will it follow from hence that the law is against, opposite to, the promises of God? By no means. They are well consistent. But yet the law cannot give life, as the promise doth. If there had been a law which could have given life - Which could have entitled a sinner to life, God would have spared his own Son, and righteousness, or justification. with all the blessings consequent upon it, would have been by that law.