Righteousness by faith is apart from the law and does no rely on observing the Sabbath:
"But now a righteousness from God, apart from the law, has been made known." - (Rom 3:21-22)
You don't need faith to observe the Sabbath according to the law, you just need to abstain from work:
"Six days you shall labor and do all your work, but the seventh day is a Sabbath to the LORD your God; on it you shall not do any work, neither you, nor your son or daughter, nor your manservant or maidservant, nor your animals, nor the alien within your gates.” – (Ex 20:8-10)
Even the animals were required to observe the Sabbath.
Abstaining from work from sunset to sunset on Saturdays does not require faith.
Many Jews today observe the Sabbath according to the law, despite their lack of faith in Christ.
Hello Doverman, righteousness is indeed by faith alone.
Are you sure you do not need faith to follow God's WORD?
So please tell us,
If God's WORD says thou shalt not kill and someone goes out and kills is that person showing their faith in God's WORD or not showing their faith in God's WORD?
If God's WORD says thou shalt not commit Adultery and someone goes out and commits Adultery is that person showing their faith in God's WORD or not showing their faith in God's WORD?
The same with all the 10 commandments if God says, to Remember the Sabbath day to keep it HOLY and no work is to be done on this day and someone goes off to work then is that person showing their Faith in God's Word or not showing their faith in God's Word?
JAMES 2:18-20; 26 [18], Yes, a man may say, You have faith, and I have works: show me your faith without your works, and I will show you my faith by my works.
[19], You believe that there is one God; you do well: the devils also believe, and tremble.
[20], But will you know, O vain man, that faith without works is dead?
[26], For as the body without the spirit is dead, so faith without works is dead also.
God's Word disagrees with you. Those who do not follow God's WORD do not have faith or do they show it.