There is a kind of longing for a display of Jesus’ power that is entirely godly, submissive, perhaps even desperate. There is another kind that puts the person making the request into the driver’s seat. Some want to see Jesus perform a sign so that they can evaluate him, assess his claims, test his credentials. At one level, of course, he accommodates himself to our unbelief by performing miracles that ought to elicit faith (John 10:38). But at another level, he cannot possibly reduce himself to nothing more than a powerful genie who performs spectacular tricks on command. As long as people are assessing him, they are in the superior position, the position of judge. As long as they are checking out his credentials, they are forgetting that God is the one who will weigh them. As long as they are demanding signs, Jesus, if he constantly acquiesces, is nothing more than a clever performer.
Thus the demand for signs becomes the prototype of every condition human beings raise as a barrier to being open to God. I will devote myself to this God if he heals my child. I will follow this Jesus if I can maintain my independence. I will happily become a Christian if God proves himself to me. I will turn from my sin and read the Bible if my marriage gets sorted out to my satisfaction. I will acknowledge Jesus as Lord if he performs the kind of miracle, on demand, that removes all doubt. In every case, I am assessing him; he is not assessing me. I am not coming to him on his terms; rather, I am stipulating terms that he must accept if he wants the privilege of my company. “Jews demand miraculous signs.”