When Jesus visited Cana again, a nobleman, an official from Capernaum came to him and begged him to come down and heal his son who was at the point of death. Jesus told him " Unless you see signs and wonder you will not believe". Instead of Jesus to go with him, he instructed him to go and that his son would live. The official believed Jesus and went away. As he was going home, one of his servants ran to meet him and told him that his son was well. When he was told the time the child got well, he discovered that it was the exact time Jesus told him to go home, that his son would soon recover.
The role of faith in the miracle is that any one that follows Jesus Christ and his teaching must have faith in him. This is because faith plays a major role in our relationship with Jesus. As the nobleman had faith in Jesus for the healing of his son, likewise any problem in our lives, be it infirmities or diseases would be healed if we have faith in Jesus Christ.