The non-reformed argues "my God would not choose some for His family and leave others to perish." Why would he say this if he really believed God can do whatever with whomever He wishes?
Free will is taught from assumption. How so? One knows that God is just and merciful. But he "assumes" that God is neither if He chooses some, and by "default" rejects others. "Free" will is a product of assumptive reaction. This is why God gave His people Romans 9:16,20,21.
16 So then it depends not on human will or exertion, but on God, who has mercy.....20But who are you, O man, to answer back to God? Will what is molded say to its molder, "Why have you made me like this?" 21 Has the potter no right over the clay, to make out of the same lump one vessel for honorable use and another for dishonorable use?
Who is the cause of this choice? GOD is. God chose Abram, then effectually called Abram. This God did with no outside influence.
If faith and obedience are the grounds of God's choice and call, then Abram caused the choice.
This system says God foresaw Abram's faith and obedience, then God chose Abram.
If this is true then Abram is precedent in God's choice.
Now God, has no choice. He is bound by Abram's choice.
Does God's choice of people for certain roles include only those who have a positive effect?
Did He not also "ordain" those who have a "so called" negative effect?
Consider what Jude said,
4For there are certain men crept in unawares, who were before of old ordained to this condemnation, ungodly men, turning the grace of our God into lasciviousness, and denying the only Lord God, and our Lord Jesus Christ.
Ordained by God for what purpose? Answer: turning the grace....denying Jesus...
Not only does God ordain righteous men to serve HIS purpose in redemptive history, but also wicked men. This is a normative action for God.
God tells us about His redemptive choice.
I Cor. 1:28-30
28God chose what is low and despised in the world, even things that are not, to bring to nothing things that are, 29so that no human being might boast in the presence of God. 30And because of him you are in Christ Jesus,....
Ephs. 1:4,5
4 even as he chose us in him before the foundation of the world, that we should be holy and blameless before him. In love 5 he predestined us for adoption as sons through Jesus Christ, according to the purpose of his will,
Phil. 1:6,29
6And I am sure of this, that he who began a good work in you will bring it to completion at the day of Jesus Christ....29For it has been granted to you that for the sake of Christ you should not only believe in him but also suffer for his sake,...
Titus 3:3-7
3For we ourselves were once foolish, disobedient, led astray, slaves to various passions and pleasures, passing our days in malice and envy, hated by others and hating one another. 4But when the goodness and loving kindness of God our Savior appeared, 5he saved us, not because of works done by us in righteousness, but according to his own mercy, by the washing of regeneration and renewal of the Holy Spirit, 6whom he poured out on us richly through Jesus Christ our Savior, 7so that being justified by his grace we might become heirs according to the hope of eternal life.
James 1:16-18
16Do not be deceived, my beloved brothers. 17 Every good gift and every perfect gift is from above, coming down from the Father of lights with whom there is no variation or shadow due to change. 18 Of his own will he brought us forth by the word of truth, that we should be a kind of firstfruits of his creatures.
I Peter 1:1-3
1Peter, an apostle of Jesus Christ, To those who are elect exiles of the dispersion in Pontus, Galatia, Cappadocia, Asia, and Bithynia, 2according to the foreknowledge of God the Father, in the sanctification of the Spirit, for obedience to Jesus Christ and for sprinkling with his blood: May grace and peace be multiplied to you. Born Again to a Living Hope 3 Blessed be the God and Father of our Lord Jesus Christ! According to his great mercy, he has caused us to be born again to a living hope through the resurrection of Jesus Christ from the dead,
I Peter 2:9,10
9But you are a chosen race, a royal priesthood, a holy nation, a people for his own possession, that you may proclaim the excellencies of him who called you out of darkness into his marvelous light. 10 Once you were not a people, but now you are God’s people; once you had not received mercy, but now you have received mercy.
I concur. But there is a great eternal difference between grace to breathe, walk, etc. and grace given unto new life.
Everybody in Abram's village was breathing, ie. receiving grace, but only Abram heard the effectual call of God's grace. The proof of God's effectual call, Abram believed.