Jesus Christ is the descendant promised to Abraham in whom all families of the earth will be blessed.
Genesis 22:18 And in thy seed shall all the nations of the earth be blessed; because thou hast obeyed my voice.
Galatians 3:8 And the scripture, foreseeing that God would justify the heathen through faith, preached before the gospel unto Abraham, saying, In thee shall all nations be blessed. 9 So then they which be of faith are blessed with faithful Abraham.
Galatians 3:16 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.
Blessing comes in the form of the forgiveness of our sins, our faith being counted for righteousness, and the gift of eternal life in the kingdom of God on the earth.
Romans 6:23 For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.
Blessings come only by believing and obeying the gospel preached by Jesus and his apostles.
Mark 16:15 And he said unto them, Go ye into all the world, and preach the gospel to every creature. 16 He that believeth and is baptized shall be saved; but he that believeth not shall be damned (condemned).
A collection of blessings known as the ‘beatitudes’ are recorded in Matthew 5
Matthew 5:1 And seeing the multitudes, he went up into a mountain: and when he was set, his disciples came unto him:
2 And he opened his mouth, and taught them, saying,
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.
5 Blessed are the meek: for they shall inherit the earth.
6 Blessed are they which do hunger and thirst after righteousness: for they shall be filled.
7 Blessed are the merciful: for they shall obtain mercy.
8 Blessed are the pure in heart: for they shall see God.
9 Blessed are the peacemakers: for they shall be called the children of God.
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.
I hope you find this helpful.