Galatians 2:21; Galatians 3:15

Galatians 2:21

21 I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain.

Galatians 3:15

15 Brethren, I speak after the manner of men; Though it be but a man's covenant, yet if it be confirmed, no man disannulleth, or addeth thereto.