Jesus' Statements Irrelevant?

Since most people who think that the law of God is abolished do not want to hear the scores of verses in the "Old Testament" that the law was going to be forever and for a perpetual covenant and so on, I was using a lot of NT verses (straight out of Jesus' mouth) to support my case. See: Jesus instructed from the Law. I pointed out:

Matthew 23:2-3 (NKJV)
Then Jesus spoke to the multitudes and to His disciples saying: “The scribes and the Pharisees sit in Moses’ seat. Therefore whatever they tell you to observe, that observe and do, but do not do according to their works; for they say, and do not do.

Jesus and his disciples did not listen to the Pharisees many times. But when they sit in “Moses’ seat” they were teaching out of the Torah. At this time Jesus commands his disciples “whatever they tell you to observe,that observe and do”.

Luke 11:28
…Yea rather, blessed are they that hear the word of God, and keep it.

Mark 7:10-13
For Moses said, Honour thy father and thy mother; and, Whoso curseth father or mother, let him die the death: But ye say, If a man shall say to his father or mother, It is Corban, that is to say, a gift, by whatsoever thou mightest be profited by me; he shall be free. And ye suffer him no more to do ought for his father or his mother; Making the word of God of none effect through your tradition, which ye have delivered: and many such like things do ye. (Also see: Matthew 15:4)

Again, Jesus is reinforcing the commandment given in Exodus 21:17 which states: “And he that curseth his father, or his mother, shall surely be put to death.”

Luke 4:4
And Jesus answered him, saying, It is written, That man shall not live by bread alone, but by every word of God. (Also see Matthew 4:4)

This was quoted from Deuteronomy 8:3. In context, this verse was talking about the law of God.

Luke 11:42
“But woe to you Pharisees! For you tithe mint and rue and all manner of herbs, and pass by justice and the love of God. These you ought to have done, without leaving the others undone. (NKJV) (Also see Matthew 23:23)

When Jesus says, “these you ought to have done, without leaving the others undone", he is reinforcing tithing.

Luke 16:28-31
For I have five brethren; that he may testify unto them, lest they also come into this place of torment. Abraham saith unto him, They have Moses and the prophets; let them hear them. And he said, Nay, father Abraham: but if one went unto them from the dead, they will repent. And he said unto him, If they hear not Moses and the prophets, neither will they be persuaded, though one rose from the dead.

When a law breaker wanted to return from the dead to warn his brothers of breaking the law, Abraham says, “They have Moses and the prophets; let them hear them.” What did Moses write to us? Moses wrote the law. It looks like from the above verse that we should “hear” him.

After I pointed out these verses and pointed her to my article Jesus Instructed From the Law the person replied:

"You continue to use NT gospels (Mat-John) to support LAW.
LAW WAS IN FULL EFFECT in Israel when Jesus came, He was born under the law so He could fulfill it. Using NT gospel verses don't support your case for being under law today.

Of COURSE He preached the law & upheld it, HE WAS UNDER IT at the time as was the rest of Israel. They also didn't have a NT written yet.

So of course Jesus is ONLY using the OT teachings of the Law & the Prophets."

If this is the case (which it is not) that would mean all the other instructions from Jesus are worthless (like the sermon on the mount and that lusting is a sin etc.)

And does her statement make sense? Does it make sense for the Son of God to come down and spend his life teaching us a whole bunch of things that won't apply to us after his death? Why did Jesus waste his time teaching us if those teachings were going to be obsolete after his death? Plus, if God said over and over and over again that the law was forever, then Jesus comes down and instructs people out of the law and also says that not one jot or tittle will pass before heaven and earth pass, why would anyone accept any writings from anyone else that contradict that? If anyone ever contradict what Yahweh (God) or Yashua (Jesus) says, then they are either liars or they are being misunderstood.

Also, since the gospels were written after the Messiah's death, why would the holy Spirit think it was important enough to include Jesus' instructions in the gospels" How would Jesus' instructions be "profitable for doctrine, for reproof, for correction, for instruction in righteousness" if they are irrelevant to us?

I would have liked to shown her the verse below, but I don't think it would have mattered, because she already thinks that Jesus' statements are irrelevant.

Luke 6:46-49
And why call ye me, Lord, Lord, and do not the things which I say?
Whosoever cometh to me, and heareth my sayings, and doeth them, I will shew you to whom he is like:
He is like a man which built an house, and digged deep, and laid the foundation on a rock: and when the flood arose, the stream beat vehemently upon that house, and could not shake it: for it was founded upon a rock.
But he that heareth, and doeth not, is like a man that without a foundation built an house upon the earth; against which the stream did beat vehemently, and immediately it fell; and the ruin of that house was great.