Why can't everyone just have their own beliefs?

Overview
A common objection to atheist activism is that atheists are attempting to disallow theists from having their beliefs. The atheist is often asked, "Why can't everyone just have their own beliefs?" Many theists assert that their beliefs are harmless, and, most of the time, they are indeed harmless. This objection arises due to a few misunderstandings:


 * Atheists aren't attempting to ban theistic beliefs, per se. Most of the time, addressing theistic beliefs is provoked out of self-defense from something a theist is doing.
 * Most of the time, the people who make this claim aren't the culprits, directly. Atheists are addressing actions of the more extreme theists.

Limits of Belief
While everyone does have their own beliefs, not all beliefs are equally valid nor do they equally reflect reality. An incorrect belief may occasionally be harmless, but it can also directly result in negative consequences. Pointing out the fallacious reasoning behind said beliefs is by no means being "harsh" or "offensive". If someone is so insecure in their beliefs as to not handle the criticism, all that shows is a lack of rationality in their beliefs.

Beliefs inform your actions, and if your beliefs are in error, your actions are most likely going to be harmful in some way. While people can hold whatever beliefs they want, it's healthier for society as a whole if those beliefs are accurate. If faith is the ground for one's beliefs and is what determines agency in the world, then not only do beliefs need to be accurate but faith needs to have a just as compelling notion that can be as plural and non-exclusive as societal norms.

Harm by Religious Belief
The following is a list of harm that religious beliefs have done. This counters the idea that theistic beliefs are harmless.


 * God won't allow global warming, because he promised not to flood us again, thus sabotaging our efforts to stem the climate issue.
 * God won't let us run out of resources - thus contributing to more destruction of the planet, avoidance of action to better our condition.
 * Son dies slowly as parents pray, in spite of easily treatable ailment.
 * The Crusades, where religion prompted a group of Christian knights to slaughter anyone in their way of securing the holy land.
 * The Spanish Inquisition, where draconian and barbaric measures were taken to ensure people stay within the Catholic church.
 * Uganda Anti-Homosexuality Bill, which is a religious-driven legislation that would jail or put homosexuals to death.
 * September 11, 2001, where faith-driven Islamic terrorists flew airplanes into the WTC, killing over 3000 people, over promises of martyrdom.
 * Catholic Anti-contraceptive effforts, which leads to an increased spread of STDs in Africa, and thus death, because the Catholic church is opposed to sexual activity.
 * The psychological damage that excessive fundamentalist indoctrination can do to one's ability to have intimate and professional relationships.
 * The unfounded and paralyzing fear of hell for minor actions, such as critical thinking.
 * The systematic deconstruction of science education in America.
 * The brainwashing of children into thinking they're worthless sinners, destroying their self esteem.
 * Mother kills child during exorcism attempt

Problem of Casual Theistic Beliefs
The problem that casual theists (such as liberal Christians) cause can be indirect. Even though most theists aren't responsible for the above atrocities, what they do accomplish is establishing a sympathetic environment for such things to occur.

It's analogous to a damp basement being a conducive environment to mold growth, versus a dry basement.