It is important to know what Under the law means, and not put our own spin on its meaning.
The first time Paul uses this term in His epistle to the Romans He says this:
Rom 3:19 Now we know that what things soever the law saith, it saith to them who are under the law: that every mouth may be stopped, and all the world may become guilty before God.
Notice that the Law only speaks to those who are under the law so that "every" mouth may stop and "all the world" be guilty.
Notice that its all the world, every mouth.
Then it says this:
Rom 3:20 Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin.
Notice that it is by the law that we have a knowledge of sin. That includes the Sabbath of the 4th commandment. Now clearly no sane person would suggest that it was sin to keep the 7th day Sabbath or any other one of the commandments. So then it is clear that the law showed sin then by showing what is good. In fact Paul is clear on this point later in the epistle:
Rom 7:7 What shall we say then? Is the law sin? God forbid. Nay, I had not known sin, but by the law: for I had not known lust, except the law had said, Thou shalt not covet.
Rom 7:12 Wherefore the law is holy, and the commandment holy, and just, and good.
Rom 7:13 Was then that which is good made death unto me? God forbid. But sin, that it might appear sin, working death in me by that which is good; that sin by the commandment might become exceeding sinful.
Notice clearly that the law here shows Paul what sin is. It does so by stating what is good. This then also includes the 7th day Sabbath which is part of that law which shows what sin is by shewing what is good. None can ignore this plain fact.
So then what then did Paul mean by under the law? Does he mean that we should not keep it and that only those who keep it are under it? It can be demonstrated that this is not the case by Paul's own writing.
Rom 6:14 For sin shall not have dominion over you: for ye are not under the law, but under grace.
Notice that sin does not have dominion over us because we are not under the law. So not being under the law is connected with being free from sin. But note the next verse which says:
Rom 6:15 What then? shall we sin, because we are not under the law, but under grace? God forbid.
So we again notice that not being under the law does not mean we can sin. Knowing without doubt that Paul believes that the law shows sin by that which is good. It is clear then that He is against the Idea that not being under the law means we do not need to obey the law. Anyone claiming such things is clearly basing their ideas of a man made doctrine.
Paul makes it clear in the next verse when he says:
Rom 6:16 Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness?
Paul is clear you either sin, which is breaking the law or you obey which is keeping the law. The topic has not changed, Paul is following a line of thought. Obedience is clearly and most obviously the opposite of sin. And Paul without controversy is clear that sin is breaking the law. Thus it is clear that those who break the commandments are in sin.
This is obvious as even those who disregard the Sabbath as a shadow will agree that the law shows sin. It is most inconsistent to suggest that once Christ comes only nine of the commandments remain sin while one changes when there is not such command or change found in all of scripture. Jesus did not teach a change, the apostles did not teach a change.
Paul uses the term under the law multiple times. but it is demonstrated that this term does not and in fact can not mean that obedience to the law is done away with. Paul is dealing with the reality that salvation comes not from the law but Christ and his atoning sacrifice for our sins.
For as Paul states:
Rom 3:23 For all have sinned, and come short of the glory of God;
It is easily demonstrated that Jesus did not come to do away with the law. Jesus mission was to save us from our sins as it is clearly seen here:
Mat 1:21 And she shall bring forth a son, and thou shalt call his name JESUS: for he shall save his people from their sins.
It is most clear throughout scripture that sin is breaking the law. Jesus came not to take the law out of the way but rather save us form sin which is breaking the law. John most convincingly speaks on this matter in like manner as Paul:
1Jn 3:4 Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law.
Sin is lawlessness. Law breaking this includes the 7th day Sabbath.
Jesus came to free us form sin and the devil as it is written:
1Jn 3:5 And ye know that he was manifested to take away our sins; and in him is no sin.
1Jn 3:6 Whosoever abideth in him sinneth not: whosoever sinneth hath not seen him, neither known him.
1Jn 3:7 Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous.
1Jn 3:8 He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil.
Notice that Jesus was manifested for the very purpose of destroying the works of the Devil which is sin. Sin is breaking the law.
So if you find yourself trying to manipulate scripture to change Gods law that shows sin. Then is it not the carnal heart which is a deceiver as it is written:
Jer 17:9 The heart is deceitful above all things, and desperately wicked: who can know it?
And as Paul most clearly reveals that it is the carnal heart not the spiritual that resists the law:
Rom 8:6 For to be carnally minded is death; but to be spiritually minded is life and peace.
Rom 8:7 Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be.
Rom 8:8 So then they that are in the flesh cannot please God.
Then it is clear that those who are of the flesh resist Gods law and are not subject to it. Jesus said if you love me you will keep my commandments.
Jesus came to free us from sin. The law says to disregard the 7th day Sabbath is just as much sin as breaking any of the other nine commandments. It is the carnal heart that manipulates scripture to make sin ok. and it is most clear that those who are truly in Jesus, those who are free are those who have overcome sin. or stopped breaking the commandments through faith in the atoning sacrifice of Jesus.
Jesus has said:
Joh 8:34 Jesus answered them, Verily, verily, I say unto you, Whosoever committeth sin is the servant of sin.
Joh 8:35 And the servant abideth not in the house for ever: but the Son abideth ever.
Joh 8:36 If the Son therefore shall make you free, ye shall be free indeed.
Those who continue to break Gods law continue to sin. These are not free but held by the flesh. But when Jesus makes us free then we shall no longer be slaves to sin to do its will. But the blood of Jesus sanctifies us by faith in His work to save us.
It is notable that Paul makes it clear that it is the carnal flesh mind that is not subject to Gods law. John makes it clear that breaking the law is sin just like Paul says. He also makes it clear that sin is the work of the Devil. So who is it that gets a man to say its now ok to break one part of Gods law?
You say how dare you suggest this. But is it not true that Satan hates most those who keep Gods commandments?
Rev 12:17 And the dragon was wroth with the woman, and went to make war with the remnant of her seed, which keep the commandments of God, and have the testimony of Jesus Christ.
IT is most clear that to suggest disobedience to even one of Gods 10 commandments is to do the work of Christ's greatest enemy. For Christ himself said:
Mat 5:19 Whosoever therefore shall break one of these least commandments, and shall teach men so, he shall be called the least in the kingdom of heaven: but whosoever shall do and teach them, the same shall be called great in the kingdom of heaven.
Mat 5:20 For I say unto you, That except your righteousness shall exceed the righteousness of the scribes and Pharisees, ye shall in no case enter into the kingdom of heaven.