Are you 100% sure of your beliefs? Have you proven them to yourself? Are you willing to bet your very existence on it?
These three was what got me to research religions in general. After all, if my everlasting life depended on my finding the right belief system and following it, I would make darn sure I know what that belief system was. For me, it was a simple choice, follow the WT or stay with my previous beliefs in Christianity. The Watchtower lost very quickly. After a while I began to see that even my previous beliefs cannot be 100% certain either.