Works of the Mosaic Law. Why do you keep ignoring this point. Paul makes this clear in verse 17, which you seem to ignore.
I somehow ignored 17?
17 And this I say, that the covenant, that was confirmed before of God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of none effect.
What WAS the 'covenant'? What WAS the 'Promise'?
Did I miss THESE as well?
11 But that no man is justified by the law in the sight of God, it is evident: for, The just shall live by faith.
12 And the law is not of faith: but, The man that doeth them shall live in them.
What you are ignoring is that Paul is speaking specifically of the Mosaic Law, unless you believe that the moral law also came 430 years after Abraham, that before Moses idolatry, murder, theft, etc. were not sins. For how could they be if the moral law only came 430 years after Abraham?