Jesus never had to speak of grace as a separate doctrine because He was grace incarnate. Why can't you see this? Do you think Paul invented something new? You keep turning the discussion away from what Jesus Himself taught and back to interpretations about the law and grace.The last thing that Lord Jesus did was to introduce the new covenant. It is the covenant of grace, not of law. There is no grace and no mercy in the law. There is no in between. Either you are living according to the law or you are living by grace.
Lord Jesus shed His blood in order to secure the new covenant for us. That's how much it cost Him. I know not so many understand this, but it is an insult to think that obeying the law is enough to please God.
The New Covenant introduces a new Law. It is the law of the Spirit of life. It is not a law in the sense of written instructions. It is the principle of being led by the Spirit and bearing the fruit of the Spirit. All the Law of Moses did was condemn sinners. It was intended to lead us to Christ.
People seem to imagine that people like me are trying to get out of being righteous. Far from it. I realised that there is nothing good in me a very long time ago. I realised that I did not have to kill my enemy in order not to offend God. I just had to hate him. That was as good as murdering him. I have never made an idol to worship, but the word of God tells me that greed is idolatry.
The law is outward observance. God requires an inner conformity to His righteousness that I could never achieve of myself. Being led by the Spirit is far more demanding than ticking boxes that tell me how well I've conformed to the Law. This was especially true when I was a new Christian. It seemed that everything I wanted in life was against God's will for me. Yet according to the law I was doing all that was required.
The law was put in charge of us to lead us to Christ. If we are born again, the Law has done its job.
I agree that God wants more than outward obedience. Jesus taught exactly that. He said that anger is the root of murder, lust is the root of adultery, and that God looks at the heart. But notice what Jesus did: He did not abolish the commandments. He took them deeper.
When Jesus said that hatred is like murder and lust is like adultery, He was not replacing the commandments. He was showing their true spiritual meaning. You say the Law only condemned sinners, yet Jesus said:"If thou wouldest enter into life, keep the commandments." (Matthew 19:17 ASV) And when asked about the greatest commandments, He answered with love for God and love for neighbour. He then said: On these two commandments the whole law hangeth, and the prophets." (Matthew 22:40 ASV)
The law was not removed. It hangs upon love. Are we allowed to remove these simple commandments on our own when jesus said to keep them? You speak of being led by the Spirit. I agree. But where does the Spirit lead us? Into obedience to God, not away from it. Jesus said:"If ye love me, ye will keep my commandments." (John 14:15 ASV), personally ,how could I not listen to him when he said;
"He that hath my commandments, and keepeth them, he it is that loveth me." (John 14:21 ASV)
The New Covenant is not God lowering His standard. It is God writing His law on the heart so that His people desire to obey Him from within instead of merely obeying outwardly. if the Spirit is leading us, would the Spirit lead us to worship other gods, make idols, dishonor parents, murder, steal, commit adultery, lie, covet, or break the commandments God spoke with His own voice? Of course not.
The difference between us is not whether God wants the heart. We both agree He does. The difference is that I believe what Jesus taught that true obedience begins in the heart and then appears in our actions. The commandments were never the enemy. Sin was the enemy. Grace does not free us from obeying God. Grace frees us from our sins so that we can through Love obey Him.
GOD said from a voice in heaven that was heard by Jesus disciples;
And a voice came from the cloud, saying, “This is My Son, whom I have chosen. Listen to Him!” (Luke 9:35)