I think that even Abraham looked forward to when all nations would be blessed (Genesis 22:18). Moses spoke of Christ (Genesis 49:10, Numbers 24:17, Deuteronomy 18:15, John 5:46). In fact, no one was justified by the Law (Galatians 2:16, 3:11). Abraham was credited with righteousness before he was circumcised, indeed, the circumcision was a seal of the righteousness of the faith which he already had (Romans 4:11). We know that through the Law, we are made conscious of sin (Romans 3:20). We know the Law was put in place, until the first coming of Christ, because of the transgressions of the people (Galatians 3:19). God presented Moses with the Law to teach His people how to be holy and to help guard His chosen people (Galatians 3:23), to help keep them on the path towards righteousness. Since we know the Law was not intended to save people, we can only agree with Paul when he said, “[t]herefore, the law was our tutor to bring us to Christ, that we might be justified by faith” (Galatians 3:24). The Law was not offered as an alternative method of salvation, but as a tutor, it is an integral part of the only method of Salvation.
I think the Law was given to God’s chosen people to provide a means of teaching them who God is, what God considers right and wrong, what God expects from those who love Him, as a means to teach how to express love for God, and ultimately to point people to Christ. But even so, if you think you can follow the Mosaic Law and not replace the grace of God with the following of these laws (Galatians 1:6-8), then feel free to do so. Paul didn’t think it was something you should do, but if you should be convinced in your own mind. Likewise, those who are convinced that there is no requirement to follow said law should show love to those who do.