You can call yourself whatever you want.
If I say I'm a good person, but constantly break the law, and cause harm, does that make me a good person because I call myself a good person?
In other words, if you profess to believe in something, then do the exact opposite of what that something teaches you to do, then you don't really believe in it do you?
Belief meaning that you believe in the cause, not so much so that you believe it's real.
Though it's a good example of the beliefs do not determine the heart of the person.
You can say what you want about the Lord changing hearts and whatever, and I believe it for some people, some do legitimately change, I did.
But I have met a good amount of nasty Christians, rather I have met a lot of nasty people.
Of all religions, Atheist included.
So we can just agree that we all suck.