Joy is an undeniable mark of a Christian believer who is full of the Holy Spirit. People may deny your doctrine, deny your faith, deny your human reasonings, but they can never deny your joy.
People sit up and take notice of joy as it enters and transforms a place.
I remember the first Holy Spirit convention I ever attended. It was the Methodist Aldersgate meeting in Savannah, Georgia in 1986. I had been perusing the brochure and noting the panel of speakers who would keynote the convention. There was one particular speaker who caught my attention by the name of Tommy Tyson. I decided I didn't like him.