"The word "proselyte" means "a person who has been converted from one religion, opinion, or party to another." To proselytize is "to make proselytes, or converts." http://www.furman.edu/~stanford/proselyt.htm
"2. By "proselytism" is meant, in particular, any direct or indirect attempt to intrude on the religious beliefs of a person of a different religious persuasion... , with the aim of undermining those beliefs, either by any kind of inducement or promise of an inducement or moral support or material assistance, or by fraudulent means or by taking advantage of his inexperience, trust, need, low intellect or naivety."