You ignore the conditions of the millennial rule and those of now.
The blessings or 'beattitudes' in (Matt. 5:3-11) can be descriptive of believers at any time. But Jesus is giving them in (Matt. 5-7) with the millennial kingdom in view. Also called in (Matthew) 'the kingdom of heaven'. This Sermon on the Mount is total Law, and even more strict than the Mosaic Law. When Jesus in (5:20) says "...except your righteousness shall exceed the righteousness of the Scribes and Pharisees, ye shall in no case enter into the kingdom of heaven.", He is still describing their duty under law. And He then gives stricter law to do and obey. Not only did you break the Law, but did you want to.
Point being... Matthew 5:20 gave the only requirement in how they can "enter" into that kingdom and the only way any one's righteousness exceeds the righteousness of the scribes and Pharisees is having His righteousness as prophesied in Matthew 5:6 as fulfilled in John 6:35 by coming to & believing in Jesus Christ.
And yet, how does one enter in if they are breaking even the least of His commandments in Matthew 5:19 and still be a part of that kingdom but being known as the least; a judgment wherein that believer can never repent of from being that least? See the conundrum?
So the commandments are for His disciples before the Bridegroom receives them into the kingdom of light as those who break His commandments are those that become vessels unto dishonor for why they are called the least in the kingdom of Heaven as received after the great tribulation.
There are 2 kinds of vessels; one unto honor..as the great and one unto dishonor as the least in 2 Timothy 2:20 as they are both in His House. It is significant to note that the vessels unto honor are the ones that depart from iniquity and thus purge themselves to be received as that vessel unto honor. 2 Timothy 2:21 That is why the call to depart from iniquity is given even to former believers 2 Timothy 2:18-19 to avoid being judged to be called the least in that kingdom of heaven.
So Matthew 5:19 talks about those in His kingdom as judged as such before entering in; and the key of entering in is by His righteousness alone as prophesied in Matthew 5:6 which is fulfilled by coming to and believing in Jesus Christ as stated by Jesus in John 6:35.
Of course we know, as you show in (John) that the New Birth is necessary for that righteousness to be obtained. But that is not Christ's emphasis with the Sermon on the Mount.
It is by that prophesy of Matthew 5:6 which links to how that righteousness is obtained in John 6:35.
The Church learns about 'faith' and 'grace' and the 'new birth', and how the believer is to act from the epistles of Paul and others. We can always go to the Mosaic Law and say that is what we should be like. There is nothing wrong with the Law. But that doesn't help the believer in Christ. Same is true with the Sermon on the Mount.
Jesus was not really talking about the Law in Matthew 5th chapter but what was to become for the saved believers while living on earth. Jesus referred to the Law as the Old Covenant and then referred to how we are to live as saved believers under the New Covenant.
In the millennium reign, let's read what it will be like.
Isaiah 65:17 For, behold, I create new heavens and a new earth: and the former shall not be remembered, nor come into mind. 18 But be ye glad and rejoice for ever in that which I create: for, behold, I create Jerusalem a rejoicing, and her people a joy. 19 And I will rejoice in Jerusalem, and joy in my people: and
the voice of weeping shall be no more heard in her, nor the voice of crying. 20 There shall be no more thence an infant of days, nor an old man that hath not filled his days: for the child shall die an hundred years old; but the sinner being an hundred years old shall be accursed. 21
And they shall build houses, and inhabit them; and they shall plant vineyards, and eat the fruit of them. 22 They shall not build, and another inhabit; they shall not plant, and another eat: for as the days of a tree are the days of my people, and mine elect shall long enjoy the work of their hands. 23 They shall not labour in vain, nor bring forth for trouble; for they are the seed of the blessed of the Lord, and their offspring with them. 24 And it shall come to pass, that before they call, I will answer; and while they are yet speaking, I will hear. 25 The wolf and the lamb shall feed together, and the lion shall eat straw like the bullock: and dust shall be the serpent's meat.
They shall not hurt nor destroy in all my holy mountain, saith the Lord.
Now how can that be the instruction for those in the millennium reign below?
Matthew 5:38 Ye have heard that it hath been said, An eye for an eye, and a tooth for a tooth: 39 But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also. 40 And if any man will sue thee at the law, and take away thy coat, let him have thy cloak also.41 And whosoever shall compel thee to go a mile, go with him twain. 42 Give to him that asketh thee, and from him that would borrow of thee turn not thou away. 43 Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy. 44 But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you;45 That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust.
Why would any one in the millennium reign smite any one on the cheek when He said no one will hurt nor destroy in all His holy mountain?
Why would any one sue at the law when everything will be provided by the Lord as well as the promise of building something and not another inhabit by civil lawsuit?
Why would ask anything from another for anything?
How can there be any enemies that hate you, despitefully use you, and persecute you in all His holy mountain?
How can the sun rise on the evil and on the good, and rain on the just and on the unjust in the millennium reign?
After the millennium reign, when Satan has been released from the pit for a small season to stage his last rebellion, yeah.. bad things will happen... but during the millennium reign? No. I cannot see how His millennium reign as prophesied in Isaiah 65 and see the Sermon on the Mount to be applicable for the inhabitants to follow in that millennum reign.
The Sermon of the Mount is applicable for saved believers now in how they will be received in the kingdom of heaven as the greats or as the leasts. It is not for salvation, but for abiding in Him which can only be done by looking to the author & finisher of our faith to help us lay aside every weight & sin.
Jesus came preaching the kingdom. That kingdom is the one promised to Israel where she will be the light of the world, and a ministering nation to all other nations on earth, with Jesus Christ her King ruling and reigning in Jerusalem. The Gospel of Matthew is the Gospel of that Kingdom, which is called by him, the kingdom of heaven.
We are to be the light of the world now.
So, yes you can make application to the believer in Christ concerning the Sermon on the Mount. But you cannot place it as a law for the believer today as part of the Church, to walk under.
Stranger
Only Jesus can show you that His commandments is not done as those that were under the law, but by faith in Jesus Christ as our Good Shepherd.