There are three indications in logic: 1- conventional indication 2- natural indication 3- intellectual indication
Miracle is intellectual indication. According to theologians, miracle is a kind of intellectual indication in scientific method.
When a prophet comes to people (from God) and presents an extraordinary affair (miracle) in order to prove his claim; either it is attributed to God or to he himself.
Undoubtedly it is the indication of his truth, because it has been done in the presence of God and if he lied, God would not let him do such an act.
This viewpoint is not accepted, because theologians do not comprehend the reality of miracle; they suppose that prophets do miracle directly by God, means they do not interfere in doing miracles!
There is a relationship between miracle and the person who performs it. Therefore miracle could not be done by a person except a prophet.
When a prophet performs a miracle, his human power is linked to Divine Power; he is granted an extraordinary determination and power.
By worshipping and obeying God, human will be able to be a complete sample of God.