Are we are under the commands of the first 5 books

[Esaias]

The two Greatest Commandments are Deuteronomy 6:5 and Leviticus 19:18:

And thou shalt love the LORD thy God with all thine heart, and with all thy soul, and with all thy might.
(Deu 6:5)

Thou shalt not avenge, nor bear any grudge against the children of thy people, but thou shalt love thy neighbour as thyself: I am the LORD.
(Lev 19:18)

Then one of them, which was a lawyer, asked him a question, tempting him, and saying, Master, which is the great commandment in the law? Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. This is the first and great commandment. And the second is like unto it, Thou shalt love thy neighbour as thyself. On these two commandments hang all the law and the prophets.
(Mat 22:35-40)

All the revealed Word of God, all of God's instruction to us, what theonomists call "God's Law", is based upon those two commandments. All of God's moral demands upon mankind are expressions in various circumstances of those two commands, to love God supremely and your neighbour as yourself.

This rules out selfishness. Sin is at its core selfishness, it is a refusal to love God supremely and to love one's neighbour as oneself. God's entire moral law can be summed up as "Love God with all you've got and love your neighbour as yourself." Since sin is transgression of the law, it necessarily follows that sin is selfishness and self centeredness. It is to love oneself above one's neighbour and above God. It is manifested by seeking one's own interests at the expense of God and others.

Many people think that because "love" is the greatest commandment, and that because "love is the fulfilling of the law", they may "love" God and others while dispensing with God's commandments. But this of course is nonsense. And in fact they themselves don't believe it. They themselves prove the lie, because they readily admit that for example loving your neighbour implies not stealing their property, or murdering them, or coveting their stuff. So they accept that the various commands of God are simply the ways to fulfill the command to love God and your neighbour, depending on the context and situation. Or to put it another way, the various commandments of God are simply expressions of HOW to love God and your neighbour in various situations and relations.

But as soon as one of those commandments interferes with their own personal wants and supposed interests, all of a sudden they find every possible way to NOT obey the command. As long as loving God and their neighbour is fulfilled in a way suitable to their own perceived self interests, all is well. But when the command requires them to deny themselves and take up their cross as it were, lo and behold "loving God and your neighbour" becomes some kind of SUBSTITUTE for the Divine instruction! How strange that loving God and one's neighbour is to be carried out by refusing to love God and one's neighbour in the context and in the manner deemed expedient by God!

So the antinomian exclaims "Oh! But I DO obey God! See here and here and there and there!" But do they really? No, they simply happen to obey God when it is convenient and when God's will just happens to align with their own. But as soon as God's will and their own depart, who do they follow? Their own will. So any obedience on their part is simply a matter of "coincidence". Much like the "blood of Jezreel" which led to the downfall of the House of Israel:

And the LORD said unto him, Call his name Jezreel; for yet a little while, and I will avenge the blood of Jezreel upon the house of Jehu, and will cause to cease the kingdom of the house of Israel.
(Hos 1:4)

Jezreel ws the location where Jehu had Jezebel tossed to her death and where the entire lineage of Ahab was wiped out, all in obedience to the words of the prophet Elijah. And immediately after overthrowing the Ahab dynasty, Jehu executed all the priests and prophets of Baal. In return, God promised Jehu the throne of Israel and that his sons would reign up to the fourth generation:

And the LORD said unto Jehu, Because thou hast done well in executing that which is right in mine eyes, and hast done unto the house of Ahab according to all that was in mine heart, thy children of the fourth generation shall sit on the throne of Israel.
(2Ki 10:30)

So why would God be interested in avenging the blood of Jezreel, and causing not only the dynasty of Jehu to cease but the entire kingdom as well? Very simply, because Jehu carried out this "holy war" for his own interests:

Thus Jehu destroyed Baal out of Israel. Howbeit from the sins of Jeroboam the son of Nebat, who made Israel to sin, Jehu departed not from after them, to wit, the golden calves that were in Bethel, and that were in Dan. And the LORD said unto Jehu, Because thou hast done well in executing that which is right in mine eyes, and hast done unto the house of Ahab according to all that was in mine heart, thy children of the fourth generation shall sit on the throne of Israel. But Jehu took no heed to walk in the law of the LORD God of Israel with all his heart: for he departed not from the sins of Jeroboam, which made Israel to sin.
(2Ki 10:28-31)

Jehu's "zeal for Jehovah" was simply a zeal for his own advancement to the throne. God's will and Jehu's aligned in this respect. But in respect of the golden calves and the fake Jehovahism set up by Jereboam Jehu had no intention of dispensing with. THAT part of God's will was at cross purposes to Jehu's, so Jehu (being selfish even in his "zeal" for God) followed his own will rather than God's.

Note: what exactly was the sin of Jereboam which was the downfall of the House of Israel?

And Jeroboam said in his heart, Now shall the kingdom return to the house of David: If this people go up to do sacrifice in the house of the LORD at Jerusalem, then shall the heart of this people turn again unto their lord, even unto Rehoboam king of Judah, and they shall kill me, and go again to Rehoboam king of Judah. Whereupon the king took counsel, and made two calves of gold, and said unto them, It is too much for you to go up to Jerusalem: behold thy gods, O Israel, which brought thee up out of the land of Egypt. And he set the one in Bethel, and the other put he in Dan. And this thing became a sin: for the people went to worship before the one, even unto Dan. And he made an house of high places, and made priests of the lowest of the people, which were not of the sons of Levi. And Jeroboam ordained a feast in the eighth month, on the fifteenth day of the month, like unto the feast that is in Judah, and he offered upon the altar. So did he in Bethel, sacrificing unto the calves that he had made: and he placed in Bethel the priests of the high places which he had made. So he offered upon the altar which he had made in Bethel the fifteenth day of the eighth month, even in the month which he had devised of his own heart; and ordained a feast unto the children of Israel: and he offered upon the altar, and burnt incense.
(1Ki 12:26-33)

Jereboam created a substitute counterfeit form of Jehovahism. He didn't tell the people to worship Baal, at least not directly. Instead, he made some idols and said THAT was Jehovah who brought Israel out of Egypt. He abandoned the Divinely ordained Feast of Tabernacles and substituted in its place some invented manmade feast in the eighth month. All as part of the new worship of the elohim that brought Israel out of Egypt. He created a fake counterfeit version of the true religion. Sound familiar?