If you don’t know where you are going how will you know what to look for? Along the path of your journey you are likely to see many signs, most of which you will probably ignore until your approach your destination.
The Pharisees demanded a sign from Jesus to test his authority. There were other prophets at the time who would promise to show people all sorts of signs. For example, they might boast of an ability to foretell the future or to heal a sick person. Jesus confounds such prophetic showmanship. It is the reason he often tells someone who has experienced his miraculous healing not to tell anyone. This is called the “messianic secret.” We might think that Jesus would want the news of his miraculous cure to spread far and wide, thinking that this would bring him more followers. However, the purpose of his miracles are not to cause faith but to confirm one’s faith. His signs do not produce faith. Rather, it is the faithful person who recognizes the authority of the Messiah in the miracle. They are the ones who truly recognize the signs.