Everyone does have their own beliefs, but all beliefs are not equally valid nor do they equally reflect reality. An incorrect belief may occasionally be harmless, but it can also directly result in negative consequences (unnecessary guilt, bigotry, racism, oppression, strife, silencing of dissent, the death of the innocent, etc.)
Beliefs direct and guide our actions, and incorrect beliefs can lead to actions that increase harm, both for the individuals holding a particular belief and those around them. A perfect example of this is the preventable deaths of children at the hands of those who wait for a god to heal instead of taking their children to a doctor. If someone dies because their faith kept them from seeking medical treatment, it is tragic. It is far more so when an innocent child is lost due to their parent’s ignorance and their reliance on a belief that is not supported by logic, evidence or reason.
Another example of beliefs harming others is the oppression and hatred directed at homosexuals, atheists and others.
A belief or opinion that is based on lies, falsehoods or misunderstandings will have consequences. It is better that our beliefs and opinions reflect the world around us, and it is often necessary to change our beliefs as new evidence becomes available.
