John Calvin Commentary John 12:37

"But though he had done so many signs before them, yet they believed not on him:" — John 12:37 (ASV)

And though he had done so many signs. So that no one may be disturbed or perplexed by seeing that Christ was despised by the Jews, the Evangelist removes this stumbling block. He does this by showing that Christ was supported by clear and undoubted testimonies, which proved that he and his doctrine were worthy of belief. However, the blind did not perceive the glory and power of God, which were openly displayed in his miracles.

First, therefore, we should believe that it was not Christ's fault that the Jews did not trust him, because through many miracles he gave ample testimony as to who he was. It was therefore unjust and highly unreasonable for their unbelief to diminish his authority. However, this very situation might lead many people to ask, with anxiety and perplexity, how the Jews could have been so dull of understanding that the power of God, though visible, had no effect on them. To address this, John proceeds further. He shows that faith does not come from ordinary human capacities but is an uncommon and extraordinary gift of God. Furthermore, it was predicted long ago concerning Christ that very few would believe the Gospel.