[Superman]

Read "The Will to Believe," a short treatise by William James.

Jean Paul Sartre said it is 'mauvaise foi' (or something like that) to say "I wouldn't do that because it's not me." Rather, the statement should be reversed. "That's not me because I wouldn't do that." In other words, our existence precedes our essense. If you do that thing, then it is you. If you do not, then it is not you.

Let's say you are a shy person who has no particular religious beliefs. If you want to change those things, go find some people who are gregarius and religious. Hang with them. Take on theri attributes and behaviors and hobbies and outlooks. After a time, you will wake up one morning a gregarious Christian.