You don't have to decide anything, All commandments, statues etc is given under the law to be followed. Breaking any commands etc in the law means breaking the whole Law. There is a confusion here for some, there is law based on works (this for the old covenant law) but also a law based on Faith for the New covenant. (see Romans 3 for the two laws). The two laws are independent of each other.
Yes, there is a lot of confusion concerning Paul's teaching, especially in Romans 3. Paul is speaking about "remission of sins", not the definition of sin. Stealing is a Sin "because" God declared "Thou shall not steal". And the wages of sin is death. All men have sinned and therefore are dead in trespasses and sins. But God from the beginning has provided for the remission of those sins. From Abel to Moses, men were shown Mercy though His Grace who, like Abraham, would repent and "
Cast away from you all your transgressions, whereby ye have transgressed; and make you a new heart and a new spirit". (Ez. 18:31)
But the Israelites HE saved from Sin (Egypt) broke His Covenant with a Golden Calf. So God "ADDED" a LAW Abraham didn't have, a temporary LAW to provide for the remission of their sins until the Prophesied High Priest of God, "After the Order of Melchizedek" should come (in their minds). This added LAW required that when a man sinned, he was required to bring a goat to a Levite Priest and kill it. The Priest would then take the blood of the sacrifice and sprinkle it on the Alter, along with other "works of this law", and through the works of this law the Priest would provide atonement for the repentant sinner. You can read about this yourself in Lev. 4.
This is what Paul called "The Law of Works" that was to lead men to the true Lamb of God. And it lead the Faithful, like David, Zacharias, Simeon and Anna, to the Christ. (Luke 1&2)
But the Priests became corrupted and used this Law as a marketing strategy to create a religious business selling the sacrifices for justification of sins. When all along what God wanted was obedience, as it is written, "To obey is better than sacrifice". For the Pharisees to accept Jesus as the Prophesied Messiah, would be the end of their business, their fame their being called "Rabbi". So they rejected the Christ and continued promoting their corrupted version of the Levitical Priesthood "works of the Law" for remission of sins.
The Law of Faith, was repent and "Yielding yourself" servants to obey God, in the belief that their sins will be forgiven by the Blood of the Lamb of God that HE offered to God for our sins, just like Abraham and David believed. This belief is called "Faith". That a man would repent of their transgressions, defined by Jesus as "Now go and Transgress God's Laws no more", turn to God, defined by Jesus as "Living by Every Word of God", and
do works "
worthy of repentance", defined by Paul as "
Let not sin therefore reign in your mortal body, that ye should obey it in the lusts thereof. Neither yield ye your members as instruments of unrighteousness unto sin: but yield yourselves unto God, as those that are alive from the dead, and your members (Body) as instruments of righteousness "unto God"."
"Many", who come in Christ's Name, would have us believe Paul is speaking to God's Definition of Sin, as the "Law of Works" for the remission of sins. But if one turns away from this world's religious system and studies for themself, "if Faith", they will find what Moses instructed a man who transgressed God's commandments to do. And Only the Anointed Priest of God can provide for the remission of a mans sin. And HE Himself said, "
I tell you, Nay: but, except ye repent, ye shall all likewise perish."
Mankind from the very beginning has chosen to judge God's Commandments, some as worthy of their respect and honor, and others as unworthy of their respect and honor. In other words, as Paul teaches, "
when they knew God, they glorified him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened. Professing themselves to be wise, they became fools,
I am a nobody, but still it seems simply a reasonable service to Yield myself to God, not judge His Commandments.
In regards to the rest (Sabbath rest) 4th command. This Rest is more than a literal or physical rest it's a "spiritual rest".