Everyone on the earth is blessed by the blessing of Abraham. His children are found among every nation, kindred, tongue, and people. Abraham's children are blessed, and through them all the families of the earth are blessed -- that is the promise of Abraham.
And I will bless them that bless thee, and curse them that curse thee; and in thee (that is, in thy Priesthood) and in thy seed (that is, thy Priesthood), for I give unto thee a promise that this right shall continue in thee, and in thy seed after thee (that is to say, the literal seed, or the seed of the body) shall all the families of the earth be blessed, even with the blessings of the Gospel, which are the blessings of salvation, even of life eternal.
Abraham 2:11
All the families of the earth are blessed by Abraham’s seed because God gives them blessings, and all those around them are blessed by the blessings of Abraham. Just being associated with the children of Abraham gives great blessings. For example, all the wonders of technology that are given by God to do the work of gathering Israel benefit everyone else in the world who are not doing the work of the Lord.
Airplanes were invented so the work of gathering Israel could happen. I can go anywhere in the world in one day, and so can the missionaries and other servants of God. Everyone else in the world, who are not servants also get to ride in planes and travel all over the earth. They get all the benefits of travel because God is blessing the children of Abraham.
Computers were invented so the work of organizing and cataloging the families of the earth could commence. The work of family history is very important to the Lord. We have been given the ability to record the genealogy of every person who ever lived. We have the ability now not just to know their names, dates, parents, and children, but even record details about their lives. Those who are not doing genealogy work also get to benefit from the knowledge God has given for His purposes -- to gather Israel.
Behold, I will do a new thing; now it shall spring forth; shall ye not know it? I will even make a way in the wilderness, and rivers in the desert. The beast of the field shall honour me, the dragons and the owls: because I give waters in the wilderness, and rivers in the desert, to give drink to my people, my chosen.
Isaiah 43:19-20
The Lord is doing something new, a marvelous work and a wonder. He sends rivers into the desert, meaning knowledge where there is none. He is giving life to the desert for Israel, His chosen people. He gives them a blessing of water to quench their thirst, and everyone else in the world is able to drink, though the blessing is not given to them because they are wicked and adulterous. They are the beasts of the field, owls, and dragons that will honor God, though they do not seek Him. They have the advantage of plenty of food and all their needs are met in spite of not being worthy, and not having kept the law. They are not blessed with the blessings of prosperity because of their own righteousness, or keeping the law, but rather God is blessing those who do. Blessings cannot be given unless there is faith, and people who are keeping the laws of God.
There is a law, irrevocably decreed in heaven before the foundations of this world, upon which all blessings are predicated—And when we obtain any blessing from God, it is by obedience to that law upon which it is predicated.
Doctrine and Covenants 130:20-21
Every blessing is given for a reason to those who keep the law upon which that single blessing is based. Because Abraham kept the law of the gospel, obtained the priesthood and sacrificed the things of the world, he was given a blessing through which all the families of the earth are blessed with the blessings of the priesthood. His priesthood lineage continues on the earth, and all those who receive it in the world, receive it through Him. These are His children -- even the Son of God receives it in the world through Him. Christ is a son of Abraham, and thus has rights to the priesthood, and He blesses every person who ever lived.
The children of Israel scattered over the whole earth who keep the laws of God are being blessed, and everyone else benefits. They are the salt of the earth.
When men are called unto mine everlasting gospel, and covenant with an everlasting covenant, they are accounted as the salt of the earth and the savor of men;
Doctrine and Covenants 101:39
A little bit of salt goes a long way in cooking. Likewise, the whole of humanity is blessed by the few people who are living the gospel and obeying the word of God. They are keeping the commandments and doing the work of God so they are blessed. When they receive their rivers of blessings, the rest of the world is also blessed -- like the whole earth being salted and having the savor just from the few people of God.
Jesus also compared this process to putting a little leavening into a loaf of bread and the whole loaf rises.
It is like leaven, which a woman took and hid in three measures of meal, till the whole was leavened.
Luke 13:21
The leavening is a teaspoon hidden in three measures of flour. There is no way to see the tiny amount of leaven, but it makes the whole three measures of flour rise. Everyone is benefited by the few who keep the commandments of God. Those who are with them, who allow the righteous to remain among them, are blessed by their presence. The whole of society is lifted up by the few who are righteous. Those who do not allow the righteous among them will not be so blessed.
Yea, and I say unto you that if it were not for the prayers of the righteous, who are now in the land, that ye would even now be visited with utter destruction; yet it would not be by flood, as were the people in the days of Noah, but it would be by famine, and by pestilence, and the sword. But it is by the prayers of the righteous that ye are spared; now therefore, if ye will cast out the righteous from among you then will not the Lord stay his hand; but in his fierce anger he will come out against you; then ye shall be smitten by famine, and by pestilence, and by the sword; and the time is soon at hand except ye repent.
Alma 10:22-23
When the society no longer allows the righteous to exist in it, then they are ripe for destruction. They no longer have any blessings of God, because He cannot give them anything since they are not keeping His laws. There is nobody left to receive blessings so the Spirit of the Lord is withdrawn from society, causing war, famine, pestilence, death, and destruction. The people of the covenant are important for the whole nation to exist.
This principle extends to the One. One man can raise up, not just a nation, but the whole world through all time. Jesus Christ is the ultimate leaven of the earth. All flesh is saved by Him. He is the leaven that causes us to rise because we cannot rise on our own. The Father blesses His Son with the blessings of Eternity because He is deserving, He has kept the law upon which that blessing is predicated. He never took of the forbidden fruit, but came to earth willingly. He was not cast out. He experienced pain, suffering, and all manner of temptation, and returned to the Father, having done all He was commanded to do. He is the One who has earned salvation for Himself. He becomes an exalted being. Because He did it by keeping the law upon which it is predicated, the whole world can go with Him. Everyone who ever lived, or who ever will live in this world are able to be raised up -- not by any worthiness on their part to receive that blessing, but only because they follow Him. He brings them with Him. The three measures of flour have no ability to rise on their own. I’m just flour. Christ is the leavening that raises me up. He blesses me with His worthiness. He is the salt of the earth. He makes the rest of us palatable to God.