Why would God create a person with borderline personality disorder ?

He doesn't.  Circumstances and environment and trauma all contribute to that.

He won't.  There condition is the results of damaging things that happened to them often early in their lives. 

I passed a car on the side of the road the other day that had steam spouting out of the radiator.  Oil leaking in a long trail behind it.  Its front bumper laying 100 feet away form the rest of the car, and part of its quarter panel pushed a couple of feet into the engine.

I did not ask myself which the engineers designed it like that, or the factory put it together that way.  I was certain its condition was related to semi that had hit it a few minutes before.

So I would not assume that a person with borderline personality disorder was created that way by God.  I would be certain that it was caused by the the force of sin which had done damage to his mind and heart.

There is no proof God exists, so your BPD is the result of genetics or trauma or other factors.

For the same reason He smites innocent children with incurable tumors.

Fun to watch.

There is no god, fredda, and nobody has ever proven otherwise.

Leave the fantasy world of silly cult belief, and come into reality.

Don't be an ignorant stooge like David at your Cervix.

As long as you don't cross that border, what's the problem?

For his glory.   God will get the glory out of every seemingly bad situation.   He will use it to a good purpose.

Because reading the Bible the Christian god clearly has a personality disorder. So he's creating people in his image