There are some things that Jesus wouldn't do. He delivered the daughter of a desperate woman from demons (15:21-28). He healed the sick, the lame, and the blind (15:29-31). He had compassion on 4,000+ spiritually and physically hungry souls and he fed them (15:29-39). But he would not perform a miracle "on demand." When the pharisees demanded a miracle as proof of his identity, he refused (16:1-4). He was not a cosmic vending machine!
Jesus did not perform miracles for the purpose of creating a show. He was not putting on a divine fireworks display. Instead, he responded to the need and the awareness of need on the part of the recipients. The story of the gentile woman (15:21-28) can be a pretty confusing one. At first it seems that Jesus is being rude. But it becomes apparent that Jesus is drawing out her faith, causing her to embrace her need and make her request on the basis of mercy. He concludes with a strong compliment - one of the strongest in the gospels - "dear woman... your faith is great."
The pharisees had plenty of evidence that pointed to the identity of Jesus. He did everything that, Isaiah the prophet said, the servant of the Lord would do. He healed the lame, gave sight to the blind...he set the captives free! Maybe the pharisees did not see the signs because they did not see themselves as needy. Instead, they came to Jesus from a position of strength. They set out the hoops and demanded that Jesus jump through them. When the disciples started to do the same thing - Jesus reacted strongly. He suspected that they forgot their bread on purpose. Perhaps they were trying to create a situation in which Jesus would do something "exciting." He warned them of this teaching and called it the "yeast of the pharisees" (16:5-6). It seemed that the trend of demanding a sign was spreading. But to those who will come to him in need, Jesus always welcomes them with compassion and grace.
Are your requests motivated by need, or a desire to see power? Do you come to God from a position of dependence, or are you looking for God to prove himself? -MK