People believe what they want to believe, not what they have to believe.
You can choose to believe something that is well-supported with facts and research, or you can choose to believe the anthesis with the facts neatly brushed under the rug. Or something in the middle.
And what you choose to believe shapes your life. The community you live in. Your rituals. The ideas you find interesting. Your opponents. Your values.
I think some people view beliefs as a non-choice, though— something that was passed down to them. But living with an unexamined belief system is also a choice.