Unconditional election - Why does God choose a person?

RO 11:5 So too, at the present time there is a remnant chosen by grace.
 
"By grace," and not due to anything in us:
 
Ephesians 2:8  For it is by grace you have been saved, through faith--and this not of yourselves, it is the gift of God...
1CO 1:30 It is because of him that you are in Christ Jesus.
 
And not because of us...

And yet there is an aspect that is usually present when God chooses people:
 
James 2:5 Listen, my beloved brethren: did not God choose the poor of this world to be rich in faith and heirs of the kingdom which He promised to those who love Him?
 
1 Corinthians 1:26-29 Brothers, think of what you were when you were called. Not many of you were wise by human standards; not many were influential; not many were of noble birth. But God chose what is foolish in the world to shame the wise; God chose what is low and despised in the world, even things that are not, to bring to nothing things that are, so that no one may boast before him.
 
Now if God is choosing those who choose him, how is it that God chose the weak? For who made those who were chosen weak? God did! They didn't make themselves weak, that is not a condition people set out to be in, in order to be chosen.

Does God choose people based on seeing that they will believe?
 
Matthew 11:21 Woe to you, Chorazin! Woe to you, Bethsaida! For if the mighty works done in you had been done in Tyre and Sidon, they would have repented long ago in sackcloth and ashes.
 
God saw that they would have repented, but yet they weren't chosen.

RO 9:11-12 Yet, before the twins were born or had done anything good or bad--in order that God's purpose in election might stand: not by works but by him who calls--she was told, "The older will serve the younger."
 
Could this be about choosing nations instead of people? The main problem here would be that there are people in many various nations who belong to God (2 Ki. 5:15, Acts 10:34-35), and corporate election is about belonging to God, and which nation do the Gentiles represent?
 
So this must be illustrating a choice of God in the area of salvation, "God has mercy on whom he wants to have mercy, and he hardens whom he wants to harden," and this is also not just specifying conditions for entry, for "who resists his will?" is not answered by a list of people who indeed resist God's will.
 
Pharaoh did not resist God's will, for he did let the people go, and clay does not choose along with the potter:
 
Romans 9:21  Does not the potter have the right...
Romans 9:22  What if God, choosing...
Romans 9:23  What if he did this...
Romans 9:28  For the Lord will carry out his sentence on earth with speed and finality.
 
So God's choice in Romans 9 is about choosing those who will really belong to him, "vessels of mercy," in "who resists his will?" the word "who" is singular, this is certainly referring to individuals, and we do not read: "which nation resists his will?"