Miracles always make believers of God see God's power that is at work in the life of humanity. Without miracles it wil be very difficult for most people to believe that there is God and with Him all things are possible. 
https://www.lds.org/bc/content/bible-videos/videos/jesus-heals-a-man-born-blind/images/jesus-annoints-a-man-born-blind.jpg[Source](https://www.lds.org/bc/content/bible-videos/videos/jesus-heals-a-man-born-blind/images/jesus-annoints-a-man-born-blind.jpg) 
Without miracles accompanying the work of ministry,  our messages will be nothing but  mere words from man. The whole Bible would been nothing but mere book, if not for signs and wonders that follows those who believe. 

Just one miracle can help a person to find answers to thousand answered questions. I believe this is the reason why God is still in the miracle business.  

A person can be taught the word of God for months and will still find it hard to comprehend or believe but with just a miracle an unbeliever will instantly believe in God's word and even change his perception about God. 

Groaning deeply again, Jesus came to the tomb. It was a cave, and a stone was lying in front of it.  Jesus said, “Remove the stone.” Martha, the dead man’s sister, told him, “Lord, there must be a stench by now, because he’s been dead for four days.  Jesus told her, “I told you that if you believed you would see God’s glory, didn’t I?” So they removed the stone. Then Jesus looked upward and said, “Father, I thank you for hearing me.  I know that you always hear me, but I have said this for the sake of the crowd standing here, so that they may believe that you sent me.”  After saying this, he shouted with a loud voice, “Lazarus, come out!”  The man who had died came out, his hands and feet tied with strips of cloth, and his face wrapped in a handkerchief. Jesus told them, “Untie him, and let him go.”Many of the Jews who had come with Mary and who had observed what Jesus did believed in him. John 11:38-45

Jesus had explained to the jews and his disciples about him being the resurrection and life but none believed in his ability to raise Lazarus back to life. 

They found it so hard to believe that a dead person could come back to life until performed the unthinkable and the impossible. Many of the Jews who hade come with Mary and Martha and had observed what Jesus did believed in him. 

Miracles help to prove what God says His word is, there is a great power inherent in God's word and it manifest in the life of those who believe through miracles. Those who believe in the word always see the great manifestations of God's power. 

I believe miracle is one of the quickest way to draw people to God. The devil knows this secret and that's why he has also caused some false prophets or men of God to engage more in the miracle business. Let's be  vigilant the end is near.