'Keep' the law of Moses has the connotation of keeping it to the letter of the law. I do not say we have to do that. I use the words 'fulfill' and 'uphold' and 'satisfy' to describe the law not being nullified and abolished in this New Covenant.
Now I know TOG endorses a complete 'keeping' of the law of Moses in this New Covenant. He has my complete and total respect because he plainly says he is not hoping to be declared righteous in and of himself for doing that, and it's certainly not prohibited, and he's probably doing it out of the same love and adoration for God that I have for God. He is my brother. Who am I to take away the legitimate expression of his love for God? That would be destroying the work of God, not establishing it.
I can appreciate your attitude.
However, it is faith expressing itself in the works of obedience, not the works of the law.
This is where so many like TOG have been taught incorrectly, by the Religion of Judaism, and not what the scriptures actually teach.
Keeping special days wearing special clothing, Mosaic Sabbath requirements, Kosher food laws and on and on... these are all the works of the law and lead people into bondage, and are not of faith.
Jesus didn't die on the cross and send The Holy Spirit to Baptize us and empower us for people to go back to doing the very things He came to redeem the children of Israel from.
20 But do you want to know, O foolish man, that faith without works is dead? 21 Was not Abraham our father justified by works when he offered Isaac his son on the altar? 22 Do you see that faith was working together with his works, and by works faith was made perfect? 23 And the Scripture was fulfilled which says, "Abraham believed God, and it was accounted to him for righteousness." And he was called the friend of God. James 2:20-23
The law is not of faith.
Without faith, it is impossible to please God.
Love expressing itself in faith, is another way of saying , being led by the Spirit of God.
JLB