At birth I was given a middle name that is not Jewish not by my parents. I never had a Brit but my mother and I have chosen the name David as my Jewish name. I was called up at my Bar Mitzvah to read the Torah with the name David. My question is, is this enough, should I officially have a naming ceremony. I no longer also wish to use the middle name that was given to me at birth not by my parents. And wish to replace it with David.