The Sabbath has far deeper meaning than the ordinances of the law or the superficial days of the week. The 4th commandment echos depth of the 7th day so that it is not forgotten, the meaning of the 7th day is the completed work of Christ upon our own lives as we once started in darkness and light was spoken into our lives starting a work that when complete will usher in rest. Christ is at work in our lives (Phil 1:6) and when that work is complete it will usher in his rest. When I read creation, when I read the law this is what I see. commandments for specific actions are covenant based and it is short-sighted to only see the command and that which it points to has come so we look to Christ to seek its fulfillment after all he is Lord of the Sabbath so he is the one with authority to give the rest of the Sabbath as he was there when it was made.
All of God's laws have deeper meanings because they are all intended to teach us how to act in accordance spiritual principles that are aspects of God's nature. For example, in 1 Peter 1:16, we are told to be holy for God is holy, which is a quote from Leviticus where God was giving instructions for how to do that, which includes keeping God's Sabbaths holy (Leviticus 19:2-3), so these instructions are intended to teach us about a deeper spiritual principle of holiness that will lead us to take actions that are examples of that principle in accordance with what God's law instructs even in situations where it does not specifically address. If someone thought that they understood the spiritual principle of love, so they no longer needed physically obey the commands to help the widow, the poor, and the orphan, then they would be missing the whole point, so correctly understanding a spiritual principle will never lead us away from taking physical actions that are examples of that principle.
The manner in which someone lives testifies about what they believe to be true about the nature of who God is, so by following God's instructions for how to be holy as He is holy, they are living in a manner that is expressing, experiencing, loving, believing in, and testifying about God's holiness, but by someone choosing not to follow those instructions, they are living in a manner that is bearing false witness against God by testifying that the God that they follow is not. If we believe that God made the world in six days, rested on the 7th, blessed it, made it holy, that God is holy, that He sanctifies us, that He saves His people out of slavery, and that Jesus is Lord of the Sabbaths, then we will live I a way that testifies about these truths by keeping the Sabbath holy rather than a way that denies them by not keeping it holy. Our wisdom should not exceed our deeds. When something is commanded as part of a covenant in order to teach us about how to act in accordance with our nature, then our primary concern should be whether we should seek by faith the live in a manner that accurately testifies about the nature of who God is and what He has done, not whether we happen to be part of that covenant.
the first chapter of Isaiah shows us that keeping the letter of the law became hateful for God and with very strong and descriptive language. v16-17 God speaks of his desires "Wash yourselves and make yourselves clean. Stop doing the evil things I see you do. Stop doing wrong! Learn to do good. Be fair to other people. Punish those who hurt others. Help the orphans. Stand up for the rights of widows.” Despite that they were keeping law God rejects their actions and puts caring for others over the lettter of the law. So there is a such thing as keeping the letter while missing the whole point just as there is a such thing as not keeping the letter yet it is still worthy.
There are many verses where obeying God's law brings life, where the Spirit has the role of leading us to obey it, and where the New Covenant involves following it, yet in 2 Corinthians 3:6, the letter of the law leads to death, so there is something about following the letter of the law that is not correctly doing what God has instructed. On the other hand, if correctly doing what God has instructed leads to death, then God is misleading His people and should not be trusted to rightly guide us. In Isaiah 1, the problem was not that that they were doing things God commanded, but that they were doing those things while their hands were full of blood. Everything in Isaiah 1:16-17 is in accordance with God's law, not doing something other than it. In Matthew 23:23, Jesus said that tithing was something that they ought to be doing, but not while neglecting weightier matters of the law of justice, mercy, and faith, so I agree that someone obey God's law while missing the whole point, though that leads to death just as assuredly as refusing to obey it, so doing the weightier matters of the law does not mean that we should neglect doing what it instructs.
Jesus himself says that doing good is lawful on the Sabbath. "doing good" of course needs to be defined in a biblical context and we are not just talking about qualitative goodness but a moral goodness as it relates to God. The 4th commandment is not a moral law as it is not an action that is motivated to help others through God. Christ asserts that we would rescue a fallen sheep on the Sabbath (Mat 12) which leads him to conclude that doing good is lawful, yet we can only see physical sheep when he says this? (or healing withered hands) Sheep is one of the strongest symbols used in the bible and certainly during the Sabbath if we are tasked with rescuing sheep then we have a lot of lawful work to be done.
Some of God's laws appear to conflict with each other, such as with priests being commanded to rest on the Sabbath, but also being commanded to make offerings on the Sabbath (Numbers 28:9-10), however, it was not the case that they were forced to sin by breaking one of the two commands no matter what they chose to do, but that the lesser command was never intended to be understood as preventing the greater command from being obeyed. This is why Jesus said in Matthew 12:5-7 that priests who did their duties on the Sabbath were held innocent, why David and his men were held innocent, and why he defended his disciples as being innocent. This is also why it is lawful to rescue a fallen sheep on the Sabbath, to circumcise a baby boy on the 8th day if it happens to fall on the Sabbath, and so forth. Some Pharisees through that it was unlawful to do work on the Sabbath and that healing is works, therefore it is unlawful to heal on the Sabbath, however, we are also commanded to love our neighbor, and no command was intended to be understood as preventing the greatest two commands from being obeyed, which is why Jesus ruled that it is lawful to do good on the Sabbath. However, the fact that there are exceptions where following another command takes priority does not mean that we should not normally follow what God has commanded.
If morality were only in regard to our relationships with man and not in regard to our relationship with God, then it would be moral to commit idolatry, but rather morality is also in regard to our relationship with God, so the keeping the Sabbath holy is also a moral law. The Bible does not make the distinction of saying that some laws are moral laws while others are not and there is no example of disobedience to any of God's laws being considered to be moral. Rather, morality is in regard to what we ought to do and we ought to obey God, so all of God's laws are inherently moral laws. God has commanded to keep the Sabbath holy, so claiming that it is not a moral law is claiming to have greater moral knowledge than God.
spreading the message of Christ far and wide is the most laudable thing we can be doing. On the Sabbath doing work motivated to spread his glory is good and is lawful. I'm not talking about preaching or professional clergy, I'm talking about looking around you and seeing who is stuck in pits and what the next step you can do at that moment to get them out of that pit. I refrain from dichotomizing work into secular/holy. All work serving Christ is holy, all work against Christ is not, I choose the motivation of the former regardless of what I am doing. Maybe that's mowing someone's lawn (on the Sabbath) or helping someone pay their taxes (on the Sabbath), or working at Mcdonald's (on the Sabbath). So long as our motivation is to show and spread the name of Christ (morally and upright) so that others may follow him our actions cannot be called unlawful. "doing good" in the way Christ describes in Mat 17 I use as a heuristic to living in all my actions. Or as Paul says in 1 Cor 9:23 "I do all this for the sake of the gospel, that I may share in its blessings."
In Matthew 4:17-23, Jesus begins his ministry with the Gospel message to repent for the Kingdom of God is at hand, and God's law is how his audience knew what sin is (Romans 3:20), so teaching people to repent from breaking it is a central part of spreading the Gospel, which includes teaching people to repent from breaking the Sabbath (Exodus 20:8-11). Breaking God's law in order to spread the Gospel completely undermines it and is not serving Christ. Christ is the embodiment of God's word, so the way to spread the name of Christ is by embodying God's word in word and in deed.
It's not about replacing a day with another and if that's your take away then you've missed the point. It's about doing it all for the sake of the gospel regardless of how you label the days of the week. Since the 4th commandment is ultimately about a salvation message then how could this be against it? it in fact is its purpose and I can't think of a better way to keep it holy.
We can use our reasoning in order to get out of obeying all sorts of God's commands, so it comes down to whether we are going to learn on our own understanding of right and wrong or whether we are going to trust God with all of our heart to correctly divide between right and wrong through His law and he will make our paths straight (Proverbs 3:1-6).
