The key to the Sermon on the Mount is that those who truly wait for Christ are blessed.
Those who are poor in spirit will receive the gospel of the kingdom. (Mt 5:3-4, Isa 61:1)
Mt 5:3 Blessed are the poor in spirit: for theirs is the kingdom of heaven. 4 Blessed are they that mourn: for they shall be comforted.
Isa 61:1 The Spirit of the Lord God is upon me; because the Lord hath anointed me to preach good tidings unto the meek; he hath sent me to bind up the brokenhearted, to proclaim liberty to the captives, and the opening of the prison to them that are bound;
To be meek is to firmly believe that God will care for the righteous to the end. (Mt 5:5)
Mt 5:5 Blessed are the meek: for they shall inherit the earth.
Blessed are those who wait for Christ, the righteous of God. (Mt 5:6)
Mt 5:6 Blessed are they which do hunger and thirst after righteousness: for they shall be filled.
Blessed is he who has mercy on souls who do not know Christ. (Mt 5:7, Mk 6:34)
Mt 5:7 Blessed are the merciful: for they shall obtain mercy.
Mk 6:34 And Jesus, when he came out, saw much people, and was moved with compassion toward them, because they were as sheep not having a shepherd: and he began to teach them many things.
The mind of the saints who are forgiven of sins by Christ and live as faithful people of the Lord (Mt 5:8)
Mt 5:8 Blessed are the pure in heart: for they shall see God.
A person who tells people that Jesus is the Christ (Mt 5:9, Nah 1:15)
Mt 5:9 Blessed are the peacemakers: for they shall be called the children of God.
Nah 1:15 Behold upon the mountains the feet of him that bringeth good tidings, that publisheth peace! O Judah, keep thy solemn feasts, perform thy vows: for the wicked shall no more pass through thee; he is utterly cut off.
Blessed are those who are persecuted because of Christ. (Mt 5:10-12, Lk 6:22-23)
Mt 5:10 Blessed are they which are persecuted for righteousness' sake: for theirs is the kingdom of heaven. 11 Blessed are ye, when men shall revile you, and persecute you, and shall say all manner of evil against you falsely, for my sake. 12 Rejoice, and be exceeding glad: for great is your reward in heaven: for so persecuted they the prophets which were before you.
Lk 6:22 Blessed are ye, when men shall hate you, and when they shall separate you from their company, and shall reproach you, and cast out your name as evil, for the Son of man's sake. 23 Rejoice ye in that day, and leap for joy: for, behold, your reward is great in heaven: for in the like manner did their fathers unto the prophets.