Why didn’t God make a covenant with the whole world then? Why did God leave the Egyptians out of the plan of salvation for Israel?
Was it because Israel was more righteous than the rest? Was it because Israel chose the right God whereas the others did not?
As St. Paul said God chose that Esau would not get the birthright but Jacob would before they did anything good or evil, before they were born.
And St Paul also said that God committed Israel to disobedience so that we could be blessed. How do you get around that?
Are you an atheist all of a sudden, or a Christian? Do you also believe God doing evil to the people of Israel must mean He is a morally corrupt being like we are?
Why did God choose twelve essentially street people to start His New Kingdom on Earth? God chooses the least worthy of recognition. He chooses sinners. He chooses the backwards, and the poor and downtrodden. He chooses the ignorant. (Which is why we hope in His mercy for those who never saw Him nor knew Him.)
He makes the weakest stronger, so they can make others stronger. Do you see all of the rich, self-righteous, and seemingly perfect people out there? It’s a façade. No man of the world, seemingly stronger than you or I, is really. He’s just as fragile as a clay doll, like you or I. He’s just as clueless as you or I. He worries as much as you or I. He sins as much as you or I. He would not be human if this were not true.
So, then, why Israel and why them alone? Because they were so much more useless?
Some Catholic scholars, like Scott Hahn and Jeff Cavins, seem to think that God was making something of a progression with Israelite history. It began with one couple (Adam and Eve). Then it became several couples, a family (Noe). Then it became several families, a tribe (Abraham). Then it became twelve tribes, a nation. Then a much larger nation under David, with alliance with some pagan nations like the Moabites. Then finally, all nations and empires under Jesus Christ, High Priest and King. Not that He was not capable of uniting us all in one instant.
That just seems to be the trend. I honestly don’t know exactly why God chose to do it that way.