Do we have questions on what our human will can and can’t do? Maybe these verses can answer those questions.
Romans 9.9-18. There are three points here to see in these verses that maybe we take for granted or don’t just ‘see’. One, is that the revelation by Paul is taken from old, abrahamic era of the old testament. This and many other things in the old testament combined are setting up a storyline about God and his eternal purpose, we have to ‘see’ these things as interwoven into the old testament as a question, which will soon be answered in the new testament.
Secondly, There is a point in just the verses from 9-13. It is God’s choice on what happens in his story, who goes where,when, and how. It is also relevant in how God interacts with his creation,(This is the greatest difference in the Jewish God, and other gods, He was a vital hands on God that was trying to show and tell the Jewish people that he was still always there for them) God allowed sarah to have a son, and he was to have a part in God’s story.
Thirdly is the verse of sixteen that says “So then it depends not on human will or exertion, but on God, who has mercy.” and 17,18 that gives an example of it. 17-“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 show my power in you,and that my name might be proclaimed in all the earth. 18 So then he has mercy on whomever he wills and he harden whomever he wills”. ESV
God’s power does not depend on humans will to continue his story but is used in the telling of it.