Believe Me

 Believe me when I tell you who I am.
(Believe anyone when they tell you who they are.)

I was once involved with someone who told me something along the lines of "People can tell me who they are, but I'm not going to believe them.  I'm going to decide for myself who they are."

And...I get that.  I really do.
Because I get that people can tell you who they are, but then their actions, their words, shit, even their entire LIFE will speak very very differently on the subject.
So, in a sense, maybe you should decide for yourself.

But at the same time...

Well, I guess it depends on the relationship you have with the person.  If I met someone, and didn't know them very well, nor have an established relationship of some sort with them, I would be more inclined to not so much listen to who they tell me they are, but rather wait and see who they show me they are.
But if someone I have known for a while tells me who they are, I'm inclined to listen.  First off, you will forever be getting to know the people in your life; that doesn't ever stop.  People are complex, but they are (or should be, at least) constantly evolving.  Which means that you can know someone for a lifetime, but still be learning new things about them.  As it should be.  But also, if I have known you for a while, I have seen who you are through your words, through my interactions with you, through who you are as an individual.  So.  That means that I know who you tell me you are will be authentic, and it will be real.

But this is so complex!
Because you meet people, and they think one way, they have viewpoints about some things, and for whatever reason, the way they think, and the outlook they have is cemented in your brain.  And then they may grow over time, they may change, and mature, and their ways of thinking and their viewpoints may change.  But then you feel inclined to think of them as a liar, or a hypocrite, because how could they switch from one side to the other?
But...oh.  If you aren't giving them the room, and grace, and courage to grow, you are forcing them into a box you made.  A box which doesn't allow them to evolve, or change their mind, or shift their perspective.

1. Give people the space and grace to grow and mature.

2. Believe people when they tell you who they are.

I have done this.
I have told someone close to me who I am.
And you know what classic mistake they make?
They think they know me better than I know myself, so they decide that who I am telling them I am, is not, in fact, who I really am.  No.  It must not be, because they know me more than I do, and they don't see it, so therefore, it must not be true.

And all I can tell you about this approach, is that it is hurtful, and it will damage the relationship you have with that person.
Instead of them feeling like you're safe, and they can be vulnerable with you, and they can reveal who they are on the deepest and most intimate levels, they will instead build up walls, they will not share themselves, they will become distant.

And is that really worth your insistence that they aren't who they told you they are?

Give people the benefit of the doubt.
Of course, it depends on the situation, and the length of time you've known them, and other factors.  But for the most part? 
Believe them.