Repelling people

I realize that I need to stand for my values in order to attract my target audience and repel others by also talking about what I’m against.

I notice that I am so afraid to repel people that I cannot even find clearly what I stand for or not. Another reason is that I know that what I believe today can change as I learn more and I am afraid to stand for things that I won’t believe anymore tomorrow.

How would you approach this to uncover first what I really stand for and also to not be afraid of changing my mind?