I am not sure that I can do justice to the meaning of supernatural joy, but I would say that for those who have experienced it at the highest level possible that this joy is “ecstasy”.
There is a form of supernatural joy that is called the “Grace of Jubilation”. It is something that is experienced in a moment and from within. I can only explain this by telling you about my first experience.
My experience happened one morning at Mass in September 1999. On that morning, I was thinking about several matters that related to East Timor. It was the feast of the Korean martyrs, and my mind had swept from Korea to the Japanese martyrs in Nagasaki, to the martyrs in East Timor (including three priests) who were gunned down in a Church, and then to the Australian troops who were about to land in East Timor to restore order. I was not expecting to read, but the lector had not arrived, and so I went up as the substitute. As I began to read the proclamation of Cyrus, a thought came: “Everything will be alright”. In an instant I knew that the East Timorese would be free to rebuild their lives. At the same time, I felt an inner excitement that caused me to read in a way that I had not read before. I was left trembling from the experience. The presider at that Mass confirmed the nature of my experience, and I wrote my own prayer concerning the way that I felt at the time and how my heart was lifted up to the Lord.
Human joy is a lower level experience again. It is that joy that you have when you give birth to your baby, or some other human experience that makes one happy but the happiness might only be fleeting.
I have had other lesser experiences that have left me with a warm fuzzy feeling or they have brought tears to my eyes as I have experienced something similar to that first occasion but not so intense.
Maggie