From the NAS Greek Lexicon for pleroo:before he died and rose he said
“Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil. For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.”
Matthew 5:17-18 KJV
after he died and rose he interpreted
“And he said unto them, These are the words which I spake unto you, while I was yet with you, that all things must be fulfilled, which were written in the law of Moses, and in the prophets, and in the psalms, concerning me.
Then opened he their understanding, that they might understand the scriptures, and said unto them, Thus it is written, and thus it behoved Christ to suffer, and to rise from the dead the third day:
and that repentance and remission of sins should be preached in his name among all nations, beginning at Jerusalem.
And ye are witnesses of these things.”
Luke 24:44-48 KJV
"to fulfil, i.e. to cause God's will (as made known in the law) to be obeyed as it should be, and God's promises (given through the prophets) to receive fulfilment"
After Jesus said that he came to fulfill the law, he then proceeded to fulfill it six times throughout the rest of the chapter by teaching how to correctly obey it as it should be. Moreover, he did not mention anything about his death in the Sermon on the. Mount. It is by the Mosaic Law that we have knowledge of what sin is (Romans 3:20), so preaching repentance and remission of sins in his name to all nations is calling for the nations to obey the Mosaic Law.
Indeed, in Romans 10:5-8 references Deuteronomy 30:11-16 as the word of faith that we proclaim in regard to saying that the Mosaic Law is not too difficult to obey and that obedience to it brings life and a blessing. In Deuteronomy 32:46-47, it is our very life. In Proverbs 3:18, it is a Tree of Life for all who take hold of it. In Proverbs 6:23, for the commandment is a lamp and the teaching a light, and the reproofs of discipline are the way of life. In Luke 10:25-28, Jesus said that the way to inherit eternal life is by obeying the greatest two commandments of the Mosaic Law. In Matthew 19:17, Jesus said that the way to enter eternal life is by obeying God's commandments. In Hebrews 5:9, Jesus has become a source of eternal salvation for those who obey him. In Revelation 22:14, those who obeyed God's commandments are given the right to eat from the Tree of Life. In Romans 2:6-7, those who persist in doing good will be given eternal life. In Romans 6:19-23, no longer presenting ourselves as slaves to impurity, lawlessness, and sin is contrasted with now presenting ourselves as slaves to God and to righteousness leading to sanctification, and the goal of sanctification is eternal life in Christ, which is the gift of God, so obedience to God's law is the content of His gift of eternal life.Did it keep anyone alive ? Even Moses it’s mediator died because of his transgression
“who also hath made us able ministers of the new testament; not of the letter, but of the spirit: for the letter killeth, but the spirit giveth life.
Moreover, in Jeremiah 31:33 and Ezekiel 36:26-27, the New Covenant involves God putting the Mosaic Law in our minds and writing it on our hearts and sending the Spirit to lead us to obey it, so 2 Corinthians 3:6 should be interpreted in a way that is in agreement with these verses rather than a way that is contrary to them. If following the letter referred to correctly following God's instructions and that leads to death, then God should not be trusted to guide us and we should not be His followers.
The fact that God's law is a ministry of life for those who obey it and a ministry of death for those who refuse to obey it is not a very good reason to refuse to obey it. The veil was preventing people from seeing that the goal of everything in Scripture is to testify about how to know Jesus, which is eternal life (John 17:3), but that veil also prevents those who reject the Mosaic Law from seeing the same thing.which vail is done away in Christ. But even unto this day, when Moses is read, the vail is upon their heart.”
2 Corinthians 3:6-7, 12-15 KJV
Ministration of death v the ministration of the spirit of life
Like a death and a resurrection