Prove that there are alot of people who are mentally unstable who believe they are the chosen one like jesus.
This is irrelevant. Most religious people are not mentally unstable. Most are just normal people with average morals who compartmentalize their beliefs.
People who are in mental hospitals because they claim to be "the chosen one" are not there because religion exists... they have underlying issues. If religion didn't exist they would latch on to something else ... like claiming they're napoleon.
Then prove that treatment is far more affective without the influences of the bible.
No medical treatment that I know of includes use of the bible in any way.
Then prove that christianity is making people unstable.
"Unstable" is taking it a bit too far. Most of the religious population are not 'unstable'. They simply indulge a bit too much in platitudes, wishful thinking and odd rationalizations in their attempts to reconcile their world view with reality.
Sure, there are 'unstable' extreme religious fundies ... but they are the minority. They're probably already unstable ... although religion may aggravate their condition.
Then help people believe that the bible is not true.
This is poorly worded. You mean help people understand their religious beliefs are unjustified due to the overwhelming lack of evidence to support the their claims... thus leading them to justified disbelief.
After that society will be more accepting and have better treatments for the mentally unwell.
How society treats the mentally unwell is a public health issue that has nothing to do with religion.
I agree that, by eliminating religions and their dogmas, we will be helping people who currently wrestle with their cognitive dissonance trying to reconcile their beliefs (and instilled fears) with reality.
Religion has a negative impact on people. But I am not going to go as far as to say that everyone with a religious belief is mentally unwell or unstable. That's just not true.