Beliefs matter. Profoundly.
Whenever you embrace a particular belief, it becomes a premise in your life. Based on that premise, your logic will compel you to act in one way or another.
For example, depending on whether you believe in God or believe there is no god, your conduct in life will be profoundly different. Based on the fundamental premise of belief, an atheist has a completely different set of logical goals, values, inhibitions and even compulsions as compared to a Christian. Actions which atheists find logically compelling can be anathema for Christians.
As another example, consider negative interest rates. That concept seems absurd to most, but to those who understand and embrace the premise of debt-based monetary system, negative interest rates are a reasonable, rational and even necessary concept. The logic of the first premise (debt-based money) compels the consequence of negative interest rates.