If nobody believed in superstition it would be unable to hurt anyone
Miracles & Weak Faith
Miracles are events that seem to be against nature or the way natural law usually runs. In other words, they cannot be explained by nature. Examples are the Blessed Virgin Mary appearing to children, the unexplained cure of incurable illness, blood coming out of nowhere on Catholic communion wafers, the sun spinning at Fatima in Portugal in 1917 and most importantly Jesus Christ coming back to life after being dead nearly three days. It is thought that only God can do these things.
If Christianity with its philosophy, theology and morality were really credible, then those who want to back it up with miracles don't show much confidence in its arguments. The Catholic Church for example boasts how St Thomas Aquinas found the gospels to be miraculously consistent with the best of philosophical thinking. God then should give us a stronger interest in philosophy so that he doesn't need to perform miracles as signs. Some of our inclinations are just there and cannot be changed much anyway. The miracles are marks of a God who though he is supposed to be almighty and in control cannot run his universe properly.
If Jesus did miracles to support the faith then he was using manipulations. He was doing magic tricks to promote his teachings for he knew his teachings couldn't stand on their own. It is as if he thought that you need to do miracles to get people to believe that they should love their neighbour as themselves. That was a great boost to our faith in ourselves! If you think you can't love your neighbour then you won't be able to.
If you would advocate something as serious as miracles because your confidence in the correctness of your religion is weak that is extremism. It is like making big claims while having little faith in them. Your claims should match the force of your belief. Any breach of that rule leads to insecurity and bigotry - the big sister of insecurity.