Rom 9:16  "So then it depends not on human will or exertion, but on God, who has mercy."

The human will is free to chose all that it desires, but the will of all mankind since Adam are held captive by what we desire. There is only one remedy the absolute sovereign free love of God. He is Absolute Love.

Rom 9:17, 18  "For the Scripture says to Pharaoh, "For this very purpose I have raised you up, that I might show my power in you, and that my name might be proclaimed in all the earth." So then he has mercy on whomever he wills, and he hardens whomever he wills."

Mercy bestowed and accepted softens and makes malleable, grateful, submissive hearts. 
Defiance in the face of mercy brings hardness of heart, unmovable, stubborn, stiff necked people. Love grows cold! We rail against God, claiming our agnosticism, our atheism.

Why would you spend so much energy on something you don't even believe in?

Some clay is soft, able to be molded into something beautiful, useful; it is all of the potters skill and desire. 

Some clay is full of impurity or has become hard and brittle, it is cast aside.  

Rom 9:20,21  "But 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?" 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?"

God is able to make a people for Himself out of even rocks!. 

Mat 3:9  "And do not presume to say to yourselves, 'We have Abraham as our father,' for I tell you, God is able from these stones to raise up children for Abraham." 

Rom 9:22-29  "What if God, desiring to show his wrath and to make known his power, has endured with much patience vessels of wrath prepared for destruction,  in order to make known the riches of his glory for vessels of mercy, which he has prepared beforehand for glory-- even us whom he has called, not from the Jews only but also from the Gentiles? As indeed he says in Hosea, "Those who were not my people I will call 'my people,' and her who was not beloved I will call 'beloved.' "And in the very place where it was said to them, 'You are not my people,' there they will be called 'sons of the apart from receiving living God.'"  And Isaiah cries out concerning Israel: "Though the number of the sons of Israel be as the sand of the sea, only a remnant of them will be saved,  for the Lord will carry out his sentence upon the earth fully and without delay."  And as Isaiah predicted, "If the Lord of hosts had not left us offspring, we would have been like Sodom and become like Gomorrah."

There is no becoming a child apart from receiving faith in Jesus Christ, Yeshua Messiah, Isa Al Masih. He is Absolute Love. 
You cannot work for it or come to deserve it you may only accept and receive His love. This is folly and cannot be understood in the natural mind. 

1Co 1:18-24  "For the word of the cross is folly to those who are perishing, but to us who are being saved it is the power of God. For it is written, "I will destroy the wisdom of the wise, and the discernment of the discerning I will thwart." Where is the one who is wise? Where is the scribe? Where is the debater of this age? Has not God made foolish the wisdom of the world?  For since, in the wisdom of God, the world did not know God through wisdom, it pleased God through the folly of what we preach to save those who believe. For Jews demand signs and Greeks seek wisdom, but we preach Christ crucified, a stumbling block to Jews and folly to Gentiles, but to those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God." 

Rom 9:30-33  "What shall we say, then? That Gentiles who did not pursue righteousness have attained it, that is, a righteousness that is by faith;  but that Israel who pursued a law that would lead to righteousness did not succeed in reaching that law.  Why? Because they did not pursue it by faith, but as if it were based on works. They have stumbled over the stumbling stone, a it is written, "Behold, I am laying in Zion a stone of stumbling, and a rock of offense; and whoever believes in him will not be put to shame."


This stumbling stone is Jesus. Will you come to faith in Him?

1Pe 2:4-10  "As you come to him, a living stone rejected by men but in the sight of God chosen and precious, you yourselves like living stones are being built up as a spiritual house, to be a holy priesthood, to offer spiritual sacrifices acceptable to God through Jesus Christ. For it stands in Scripture: "Behold, I am laying in Zion a stone, a cornerstone chosen and precious, and whoever believes in him will not be put to shame."  So the honor is for you who believe, but for those who do not believe, "The stone that the builders rejected has become the cornerstone," and "A stone of stumbling, and a rock of offense." They stumble because they disobey the word, as they were destined to do.  But 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.  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."