Romanos 4

16 So the promise is based on trusting God. It is provided as a free gift, guaranteed to all the children of Abraham—not merely to those who follow the law,*4:16. Paul is not saying here that those who obey the Mosaic law are consequently made right with God—he has already dealt with that issue. He is simply pointing out that those who are not following the Mosaic law are not excluded by God. but also to those who trust like Abraham, the father of us all.