My 2-cents -- and like the OP, not looking for any rancor. Just saying my part.
Right after Matthew 5:17-19 comes the rest of the chapter where Jesus gives us examples from the Law and the new standard of the Kingdom.
He sets the stage in v. 20 with, "For I say to you that unless your righteousness surpasses that of the scribes and Pharisees, you will not enter the kingdom of heaven."
The scribes and Pharisees certainly kept the letter of the law, yet that is not enough for the Kingdom.
He then goes on to give us examples, showing how high the minimum standard of the Kingdom is compared to the 'letter' of the Law:
- Do not commit adultery? Do not lust.
- Do not murder? Do not hate.
- Do not make a false oath? Make no oath at all.
- An eye for an eye? Not so much.
- Love your neighbor? Love your enemy.
And, going to the 3rd and 4th chapters of the letter to the Hebrews:
- Rest on the seventh day from all physical work? Rest forever in Christ from all works toward salvation.
There is a difference between the day in which Christ taught and the Kingdom age we live in today. They were under the Law firmly, as a taskmaster; we have it as a teacher. They were looking toward an earthly salvation; Christ brought something much, much better (wow, what an understatement!).
This is why some people accuse Paul of teaching a different Gospel -- they don't fully comprehend the magnificent, words-cannot-describe difference Christ's atonement made in absolutely everything, everywhere (all realms), for all time, and in one moment. Black and white, day and night, up and down pale in comparison to the difference between then and now and it happened so fast your head would spin if you could see it.
The Law was not enough. Christ fulfills it, completes it, gives life to it so that it can be kept sufficiently by those keeping it that they may be granted membership in of the Kingdom through His righteousness alone.
In His atonement we find salvation and reconciliation with the Father, and Father seals/amplifies our bond with Him by gifting us with the Holy Spirit.
The Holy Spirit indwells us, writing His Law -- in Kingdom standards -- on our hearts, minds, and wills, the nearer we draw to Him.
And we obtain that nearing/nearness through communion with Father, Son, and Holy Spirit (through prayer, the Word, worship, praise, obedience, etc.) and in fellowship with and service to one another. Living in Him, by Him, and through Him more and more each and every day until our glorification in Him is completed.
Thus even today the key tenets of the law -- love the Lord your God with all your heart, mind, body and soul, and your neighbor as yourself -- are fully kept, obeyed, and honored by those who are in Christ Jesus.
Again, JMHO