Romans 9:16 So then [it is] not of him that willeth, nor of him that runneth, but of God that sheweth mercy.

I have always submitted to others interpretation concerning this passage because there did not appear to be any obvious error. That being, those who runneth were those who were attempting to get away or avoid the mercy of God. But that is exactly opposite of its true meaning. When properly understood, it is speaking of those who are exerting themselve to obtain it, as if by running a race with intent on winning.

It is not by the desire of the person who intends, or decides, to recieve mercy, nor is it of the person that exerts himself, or strives hard to attain mercy. It is only by the desire of God, who extends His mercy and compassion, that a person is able to obtain it.