Christians believe in miracles because they may believe that they themselves have experienced a miracle. This may make them believe that miracles are real. However non-believers argue that if miracles were real they would happen every day not just a one off. Christians believe that miracles are God intervening in the world.
They believe miracles are real, they believe that God is acting upon the world in his own way through the use of human beings. They believe that Jesus was a miracle sent from God to perform miracles to people with use of ‘miracle healings’ and other things. However people may argue that these ‘miracle healings’ were just coincidences.
Some Christians are persuaded by the miracles at Lourdes and the Virgin Mary appearing to Bernadette Soubirous. Also the water at Lourdes from the fountain is said to have special powers to heal. However there is no scientific evidence of the water actually having ‘special powers’ and this is an argument against miracles and also the Bernadette may have just been imaging things and the people being healed by the water maybe was just a coincidence they survived a terminal illness.
Christians believe in miracles because they say that they have experienced one. However when someone says they have experienced a miracle maybe that was just a miracle to themselves. Other people may believe in miracles as they suit them for example the people who have no water in Africa or something similar and suddenly a new water well appears they believe that, that would be a miracle but just in a different perspective.