Many former Christians and people who primarily have Christianity as a point of reference for what religion is do need to learn that Christianity is a highly orthodoxic religion - that is to say, it emphasizes correct belief. However, some religions are more orthopraxic - they emphasize correct practice.
Orthopraxic religion isn't necessarily rigidly inflexible in what's considered the correct way to practice things, and orthodoxic religion can be pretty strict about the proper way to perform its rituals. But within an orthopraxic religion, you don't necessarily have to believe that the gods actually exist or exist in a certain way in order to be considered part of it. There's nothing specific that you must believe in your heart. You just have to participate in its rituals and practices, whatever those are.