John Calvin Commentary John 9:18

"The Jews therefore did not believe concerning him, that he had been blind, and had received his sight, until they called the parents of him that had received his sight," — John 9:18 (ASV)

But the Jews did not believe. Two things here should be observed: that they do not believe a miracle has been performed, and that, being willfully blinded through a perverse hatred of Christ, they do not perceive what is manifest. The Evangelist tells us that they do not believe. If the reason is asked, there can be no doubt that their blindness was voluntary. For what prevents them from seeing an obvious work of God placed before their eyes; or, after having been fully convinced, what prevents them from believing what they already know, except that the inward malice of their heart keeps their eyes shut? Paul informs us that the same thing takes place in the doctrine of the Gospel, for he says that it is not hidden or obscure, except to the reprobate,

whose understandings the god of this world has blinded, (2 Corinthians 4:3, 4)

Warned by such examples, let us learn not to bring upon ourselves those obstacles that drive us away from the faith. By the Jews, the Evangelist means that part of them who held the government of the people.