Theonomy vs. Antinomianism


Does the New Covenant require Christians to study the Old Testament Scriptures and obey the commandments found therein? Abraham did. God blessed Abraham because

Abraham obeyed My voice, and kept My charge, My commandments, My statutes, and My laws.
Genesis 26:5

And if you are Christ's, then you are Abraham's seed,
and heirs according to the promise.

Galatians 3:29

Should the Christian's attitude toward God's commandments be the same as that of Abraham?

It is popular in many Christian circles to say that Christians are "under grace, not law," and therefore are not obligated to keep those commandments. We should not have Abraham's attitude, we are told.

For each of the New Testament passages below, the reader is invited to suggest another New Testament passage that overrules it.

(Matthew 5:17-20) "Do not think that I have come to abolish the law or the prophets; I have come not to abolish but to fulfill. {18} For truly I tell you, until heaven and earth pass away, not one letter, not one stroke of a letter, will pass from the law until all is accomplished. {19} Therefore, whoever breaks one of the least of these commandments, and teaches others to do the same, will be called least in the kingdom of heaven; but whoever does them and teaches them will be called great in the kingdom of heaven. {20} For I tell you, unless your righteousness exceeds that of the scribes and Pharisees, you will never enter the kingdom of heaven. Which New Testament passage overrules these words of Jesus, and tells us to break God's Commandments, and teach others to do the same?
(Deuteronomy 6:5) You shall love the LORD your God with all your heart, and with all your soul, and with all your might.

Jesus said this commandment is the greatest:

(Matthew 22:38) This is the first and great commandment.

Isn't the Christian obligated to obey this commandment?
(Leviticus 19:18) 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.

Jesus said this commandment is the second greatest:

(Matthew 22:40) On these two commandments hang all the law and the prophets.

Isn't this an endorsement not only of the second greatest commandment, but of all the law and the prophets?

How can someone who follows Christ say we're not obligated to obey the commandments found in the Old Testament Scriptures?

(1 John 5:3) For this is the love of God, that we keep His commandments: and His commandments are not grievous. When John wrote his letter, what did his readers understand by the word "God's Commandments?" Was it not the Scriptures of the Old Testament?
(2 Timothy 3:14-17) But continue thou in the things which thou hast learned and hast been assured of, knowing of whom thou hast learned them; {15} And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus. {16} All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: {17} That the man of God may be perfect, thoroughly furnished unto all good works. Timothy learned the Scriptures of the Old Testament in a Godly Jewish home. These are the same Scriptures many Christians say we are not obligated to obey. What New Testament verse says Christians should not continue in the Scriptures, and become thoroughly furnished unto all good works?
   

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