The Law is our tutor to lead us to Christ. Under the new covenant, we have the Holy Spirit within us to remind us to follow God's commandments:
But before faith came, we were kept in custody under the law, being shut up to the faith which was later to be revealed. Therefore the Law has become our tutor to lead us to Christ, so that we may be justified by faith. But now that faith has come, we are no longer under a tutor. For you are all sons of God through faith in Christ Jesus. (Galatians 3:26 NASB)
I will give you a new heart and put a new spirit within you; and I will remove the heart of stone from your flesh and give you a heart of flesh. I will put My Spirit within you and cause you to walk in My statutes, and you will be careful to observe My ordinances. (Ezekiel 36:26 NASB)
There is nothing wrong with eating or not eating meat, keeping or not keeping the sabbath, as long as you do so according to faith:
One person regards one day above another, another regards every day alike. Each person must be fully convinced in his own mind. He who observes the day, observes it for the Lord, and he who eats, does so for the Lord, for he gives thanks to God; and he who eats not, for the Lord he does not eat, and gives thanks to God. (Romans 14:5-6 NASB)
I know and am convinced in the Lord Jesus that nothing is unclean in itself; but to him who thinks anything to be unclean, to him it is unclean. For if because of food your brother is hurt, you are no longer walking according to love. Do not destroy with your food him for whom Christ died. (Romans 14:14-15 NASB)