Why did I see the devil in a Christan church?

Ok so I was a little boy and this was about my second time going to church. And I was with my mother when we went to the church. And when the service started being young I was being very hyper so my mom told me to go play in the toy room. And so I walked to the toy room and I saw a mirror and started playing with the toys for about 5 minutes everything was fine. And then the door was slammed shut and I saw him in the mirror. He had two horns on top of his head and they were about 8 inches. And then he started to laugh and said im going to get you. Then after that I ran to the door It was closed but it also was not lock but i couldn't open it and he was still laughing and about 15 seconds later he was gone I was able to open the door and started running and screaming to my mother and I told her what happened. I don't really think she belived me but we left after that. So please tell me what all of this means plus im writing this about 13 years later.