On virtually all occasions when Jesus performed a miracle, he required a public profession of faith before he healed or exorcised someone. In all, the gospels record thirty-seven miracles of our Lord from among the countless ones he did perform. Here are several of them.
Jesus healed the royal official’s son of his sickness after the man publicly begged him in faith: "“Sir, come down before my child dies.” Jesus replied, "Your son will live.” The boy was cured of his fever at that precise moment, and that’s because his father had travelled all the way from Capernaum to Galilee to implore Jesus to heal his son (John 4:43-54). The father’s faith cured him.
Even when someone wasn’t capable of making a public declaration of faith, Jesus still required one to be made by intellectual assent before he would act. Jesus drove out an impure spirit from a man who was possessed by a demon only after it had declared in the synagogue: "I know who you are—the Holy One of God!” With that, “the impure spirit shook the man violently and came out of him with a shriek” (Mark 1:21-27).
There’s the Roman centurion, a Gentile, whose servant was gravely ill and about to die, so having heard about Jesus, he sent some Jewish elders to ask Jesus to come and heal his servant. Meanwhile, the servant had died while our Lord was going to the centurion’s home. Still, the centurion believed that Jesus had the authority to restore his servant to life. He sent his friends to meet Jesus and give him a message which amazed our Lord who responded: "“I tell you, I have not found such great faith even in Israel.” When the centurion’s friends returned to his home, they found the servant alive and well. Jesus acted upon the centurion’s message. The man believed not only that Jesus had the power to raise his servant from the dead, but also he could do it without actually being present in his house (Luke 7:1-10).
When a man with leprosy came and knelt before Jesus in public and cried out, “Lord, if you are willing, you can make me clean,” our Lord reached out and touched the man, saying, ““I am willing. Be clean!” The leper was healed immediately. And as a further obligation of faith, the man was instructed to “go, show [himself] to the priest and offer the gift Moses commanded, as a testimony to them”. Unfortunately, the man couldn’t contain all his excitement and instead went about telling everyone what Jesus did for him which, in a sense, was still giving public testimony. Of course, Jesus told the man not to tell the priests what he had done for him, but this was because our Lord wished to reserve this prerogative for himself at a later time when he would appeal to his works before the Pharisees in his revelation of himself (Mark 1:40-45; cf. Matthew 9:1-8).
There was a woman who had had a hemorrhage for twelve years. One day she was among a crowd, and as Jesus passed by she touched his cloak. Feeling that power had gone out from him, Jesus asked, “Who touched me?” This was a rhetorical question on his part that was meant to prompt the woman to reveal herself to him in public. In other words, she was called to give testimony to her act of faith. In fear and trembling, the woman ‘came and fell down before him’ and admitted that it was she who had touched him. Only then would Jesus say to her: “Daughter, your faith has made you well; go in peace and be healed of your affliction” (Mark 5:25-34).
Thus, before Jesus would perform his first and most important miracle, not in compassion for the wedding guests in their want of wine, but rather for humanity in its want of grace, his mother Mary had to first profess her faith in him and trust in God, since it was on this occasion she knew that their relationship would radically change. When Jesus insinuated that she knew what she was really asking, that his hour had in fact arrived now that he would start his public ministry in the shadow of the cross, he wanted to hear her say “Yes” despite all the sorrow she would have to suffer, a sorrow far greater than that for not being able to provide a proper place for his birth and going into exile with him to Egypt. Jesus implicitly wanted a testimony from her as to whether she was just his mother or more importantly a disciple of his, whether she was prepared to go through with it all. Her response was what she adjoined the servants to do. What Jesus did before he approached the servants with his instructions was have his mother confirm her faith and renew her pledge to collaborate with God (Luke 1:38). And by doing so, her motherhood would be redefined as the Father intended and formally ratified by the Son on the cross (John 19:26-27). By her solicitation, in keeping with her calling, his mother Mary would be the mother of all her Son’s faithful disciples. “Rather blessed are those who hear the word of God and keep it” (Luke 11:28). Mary was more than a mother to Jesus. More importantly, she was a woman of faith, which she had to be if she were to be the Mother of the Church.
"Just see if it isn’t as I say. While the Lord was passing by, performing divine miracles, with the crowds following him, a woman said: Fortunate is the womb that bore you. And how did the Lord answer, to show that good fortune is not really to be sought in mere family ties? Rather blessed are those who hear the word of God and keep it (Lk 11:27-28). So that is why Mary, too, is blessed, because she heard the word of God and kept it. She kept truth safe in her mind even better than she kept flesh safe in her womb. Christ is truth, Christ is flesh; Christ as truth was in Mary’s mind, Christ as flesh in Mary’s womb; that which is in the mind is greater than what is carried in the womb."
St. Augustine, Sermon 72, 7