Why did Jesus perform Miracles? It was to prove his divinity and who he was, the miracles I have seen have all led to people becoming believers, just as it was with Jesus. I have had healing a miracle if you like, When I gave testimony of this in my church the following Sunday, a number of people were spoken to by what I said and it impacted on their lives and changed how they thought and acted.
I also heard first hand account from one of our church members who ran a soccer event, how one lad playing Soccer twisted his knee, started to swell up, couple of Christians running the event prayed over him, and the swelling went down, the pain went, he jumped up and continued to play, the parents saw this and instantly became believers and accepted Christ a few days later.