Galatians 3:18 - And the winner is...

"For if out of law [is] the inheritance, [it is] no longer out of promise.  But to Abraham through a promise God has graciously given [it]."

-Where there are sons - and sons of sons (i.e. descendants), there are heirs.  And as Paul just pointed out (Galatians 3.7), we - those who are of the faith of Abraham - are sons (and daughters) of Abraham.  God’s promise to Abraham was not only one of blessing but also descendants, that Abraham would have innumerable descendants, too many to count (Genesis 13.16, 15.5, 16.10).  Surely the two go hand in hand.  Yes, we do read of physical descendants who would possess the land of Canaan (Genesis 17.8 et al) and who would observe the covenant of circumcision (Genesis 17.10) and who would be named through Isaac (Genesis 17.19).  Yet the spiritual blessing of justification through faith to all nations would be conveyed by those who circumcise not their bodies but their hearts, carried in the hearts and by the feet and lips of those Gentiles (as well as Jews) who become a spiritual son (or daughter) of Abraham when they trust in the Lord just as Abraham did.

-In this instance (and in every other), the law and the promise are antithetical, diametrically opposed.  It's the law versus the promise, and there's not room enough in this town for the both of them.  They are mutually exclusive, entirely incompatible.  Law-based righteousness comes entirely on the basis of works.  Self-effort - it is merit-based.  At least that's the idea - it sounds good in theory but real life applications are fundamentally flawed.  Work hard, work harder - and make yourself perfect.  Perfect enough to be right in God's eyes.  Ain't gonna happen.  Whereas promised-based righteousness comes strictly on the basis of faith.  It is grace-based.  That is the word which Paul uses here - grace.  A grace gift, this, this right-standing with God.  Free, overflowing, underserved favor, straight from the heart and hand of God Himself.   And the winner is... you.  And me.  And anyone who takes their stand not on flawed works but on the steady and sure promise of almighty God.