If we are Christians, we follow the law of Christ (to which Paul referred in 1 Cor 9:1 and Gal 6:2) and not the Law of Moses. Most of Jesus' teachings which have come down to us (laws if you will) are found in Matthew 5, 6, and 7. He often contrasted his teachings with those of the Law of Moses by saying, "It was said to you of old time ..., but I say to you..." Jesus didn't say that GOD had given these commandments in the old days, but just that "It was said." Who said these things of old time? Moses, and other Hebrew prophets and teachers.
You have heard that it was said to those of old, ‘You shall not murder; and whoever murders will be liable to judgment.’ But I say to you that everyone who is angry with his brother will be liable to judgment; whoever insults his brother will be liable to the council; and whoever says, ‘You fool!’ will be liable to the hell of fire. (Matt 5:21-22)
Here Jesus teaches that anger and insult and name-calling originate from the same hateful heart as murder.
You have heard that it was said, ‘You shall not commit adultery.’ But I say to you that everyone who looks at a wife with desire has already committed adultery with her in his heart. (Matt 25:27,28)
Again Jesus' prohibition exceeds that of the law. For a man to look at a wife with sexual desire is adultery within his heart.
Again you have heard that it was said to those of old, ‘You shall not swear falsely, but shall perform to the Lord what you have sworn.’ But I say to you, Do not take an oath at all, either by heaven, for it is the throne of God, or by the earth, for it is his footstool, or by Jerusalem, for it is the city of the great King. And do not take an oath by your head, for you cannot make one hair white or black. Let what you say be simply ‘Yes’ or ‘No’; anything more than this comes from evil. (Matt 5:33-37)
Once again, Christ's law is stricter. Do not only refrain from swearing falsely, but refrain from swearing at all.
You have heard that it was said, ‘An eye for an eye and a tooth for a tooth.’ But I say to you, Do not resist the one who is evil. But if anyone slaps you on the right cheek, turn to him the other also. And if anyone would sue you and take your tunic, let him have your cloak as well. And if anyone forces you to go one mile, go with him two miles. Give to the one who begs from you, and do not refuse the one who would borrow from you. (Matt 5:38-42)
This time, the law of Christ differs from the ancient Hebrew law. ‘An eye for an eye and a tooth for a tooth.’ is vengeance for wrong doing. But Jesus taught non-resistance rather than vengeance, and doing even more than that which others demand of you.
You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’ But I say to you, Love your enemies and pray for those who persecute you, so that you may be sons of your Father who is in heaven. For he makes his sun rise on the evil and on the good, and sends rain on the just and on the unjust. (Matt 5:43-45)
Another case in which Christ's law is the opposite to the ancient Hebrew law. I am aware that we cannot find the injunction "‘You shall love your neighbor and hate your enemy’ in the Old Testament. But it is implied, and was probably taught as a law by some of the Hebrew leaders.
Again, if we are Christians we are obligated to follow the law of Christ, but have no obligation at all to follow the laws of the ancient Hebrews.
I am under the understanding that both the law of Christ and the Holy Spirit in no way disagree with the Law of Moses, God's Law. There is no other way for the standard of justice and righteousness to be stricter (are you referring to Hebrews 10 or to Matthew 5:20?). As for vengeance it is strictly forbidden by the scriptures.
Deuteronomy 32:35, 43 NASB - 35 'Vengeance is Mine, and retribution, In due time their foot will slip; For the day of their calamity is near, And the impending things are hastening upon them.' ... 43 "Rejoice, O nations, with His people; For He will avenge the blood of His servants, And will render vengeance on His adversaries, And will atone for His land and His people."
Romans 12:19 NASB - 19 Never take your own revenge, beloved, but leave room for the wrath of God, for it is written, "VENGEANCE IS MINE, I WILL REPAY," says the Lord.
Hebrews 10:30 NASB - 30 For we know Him who said, "VENGEANCE IS MINE, I WILL REPAY." And again, "THE LORD WILL JUDGE HIS PEOPLE."
Remember, the Law is about love.
Deuteronomy 6:5 NASB - 5 "You shall love the LORD your God with all your heart and with all your soul and with all your might.
Deuteronomy 10:12 NASB - 12 "Now, Israel, what does the LORD your God require from you, but to fear the LORD your God, to walk in all His ways and love Him, and to serve the LORD your God with all your heart and with all your soul,
Deuteronomy 30:6 NASB - 6 "Moreover the LORD your God will circumcise your heart and the heart of your descendants, to love the LORD your God with all your heart and with all your soul, so that you may live.
Leviticus 19:18 NASB - 18 'You shall not take vengeance, nor bear any grudge against the sons of your people, but you shall love your neighbor as yourself; I am the LORD.
Matthew 22:34-40 NASB - 34 But when the Pharisees heard that Jesus had silenced the Sadducees, they gathered themselves together. 35 One of them, a lawyer, asked Him a question, testing Him, 36 "Teacher, which is the great commandment in the Law?" 37 And He said to him, " 'YOU SHALL LOVE THE LORD YOUR GOD WITH ALL YOUR HEART, AND WITH ALL YOUR SOUL, AND WITH ALL YOUR MIND.' 38 "This is the great and foremost commandment. 39 "The second is like it, 'YOU SHALL LOVE YOUR NEIGHBOR AS YOURSELF.' 40 "On these two commandments depend the whole Law and the Prophets."
Mark 12:29-34 NASB - 29 Jesus answered, "The foremost is, 'HEAR, O ISRAEL! THE LORD OUR GOD IS ONE LORD; 30 AND YOU SHALL LOVE THE LORD YOUR GOD WITH ALL YOUR HEART, AND WITH ALL YOUR SOUL, AND WITH ALL YOUR MIND, AND WITH ALL YOUR STRENGTH.' 31 "The second is this, 'YOU SHALL LOVE YOUR NEIGHBOR AS YOURSELF.' There is no other commandment greater than these." 32 The scribe said to Him, "Right, Teacher; You have truly stated that HE IS ONE, AND THERE IS NO ONE ELSE BESIDES HIM; 33 AND TO LOVE HIM WITH ALL THE HEART AND WITH ALL THE UNDERSTANDING AND WITH ALL THE STRENGTH, AND TO LOVE ONE'S NEIGHBOR AS HIMSELF, is much more than all burnt offerings and sacrifices." 34 When Jesus saw that he had answered intelligently, He said to him, "You are not far from the kingdom of God." After that, no one would venture to ask Him any more questions.
Luke 10:25-28 NASB - 25 And a lawyer stood up and put Him to the test, saying, "Teacher, what shall I do to inherit eternal life?" 26 And He said to him, "What is written in the Law? How does it read to you?" 27 And he answered, "YOU SHALL LOVE THE LORD YOUR GOD WITH ALL YOUR HEART, AND WITH ALL YOUR SOUL, AND WITH ALL YOUR STRENGTH, AND WITH ALL YOUR MIND; AND YOUR NEIGHBOR AS YOURSELF." 28 And He said to him, "You have answered correctly; DO THIS AND YOU WILL LIVE."
The Law has not been abolished.
Matthew 5:17-20 NASB - 17 "Do not think that I came to abolish the Law or the Prophets; I did not come to abolish but to fulfill. 18 "For truly I say to you, until heaven and earth pass away, not the smallest letter or stroke shall pass from the Law until all is accomplished. 19 "Whoever then annuls one of the least of these commandments, and teaches others to do the same, shall be called least in the kingdom of heaven; but whoever keeps and teaches them, he shall be called great in the kingdom of heaven. 20 "For I say to you that unless your righteousness surpasses that of the scribes and Pharisees, you will not enter the kingdom of heaven.
It is all important, not just some of it.
Matthew 23:23 NASB - 23 "Woe to you, scribes and Pharisees, hypocrites! For you tithe mint and dill and cummin, and have neglected the weightier provisions of the law: justice and mercy and faithfulness; but these are the things you should have done without neglecting the others.
Luke 11:42 NASB - 42 "But woe to you Pharisees! For you pay tithe of mint and rue and every kind of garden herb, and yet disregard justice and the love of God; but these are the things you should have done without neglecting the others.
Following God and Jesus is not too difficult.
Matthew 11:30 NASB - 30 "For My yoke is easy and My burden is light."
It does involve being obedient to God's commands.
Deuteronomy 30:11-14 NASB - 11 "For this commandment which I command you today is not too difficult for you, nor is it out of reach. 12 "It is not in heaven, that you should say, 'Who will go up to heaven for us to get it for us and make us hear it, that we may observe it?' 13 "Nor is it beyond the sea, that you should say, 'Who will cross the sea for us to get it for us and make us hear it, that we may observe it?' 14 "But the word is very near you, in your mouth and in your heart, that you may observe it.
1 John 5:3 NASB - 3 For this is the love of God, that we keep His commandments; and His commandments are not burdensome.
John 1:41, 49 NASB - 41 He found first his own brother Simon and said to him, "We have found the Messiah" (which translated means Christ). 49 - Nathanael answered Him, "Rabbi, You are the Son of God; You are the King of Israel."