In my daily Bible reading I came across this rather difficult verse – difficult because it seems harsh. It is preceded by the hypothetical question posed by Paul in Romans 9:19-20 [as a possible rebuttal to his line of reasoning regarding God choosing some to be His and others who won't listen in the previous verses],
Well then, you might say, “Why does God blame people for not listening? Haven’t they simply done what he made them to do?” No, don’t say that. Who are you, a mere human being, to criticize God? Should the thing that was created say to the one who made it, “Why have you made me like this?” (NLT)
Paul is making the argument in this verse (and as one of the themes of this letter) that although the Jews are God’s chosen people and that has not changed – that doesn’t mean that they will be the only recipients of His promise and His mercy. In verse 16, Paul had said,
So receiving God’s promise is not up to us. We can’t get it by choosing it or working hard for it. God will sho mercy to anyone he chooses. (NLT)