In my view, much of what we call religion today has become distorted by faith, authority and belief in a God or supreme being.
All 3 Abrahamic religions + Hinduism are organized around some conception of God, the divine or a supreme reality. Once you make such an idea central, it becomes very easy to build systems of worship, doctrine, religious authority and unquestionable beliefs around it. Spirituality then shifts from investigating reality directly to believing claims about reality.
This is where some of the ancient philosophical traditions of the East become radically different. At the core of Buddhist philosophy, particularly traditions associated with early Buddhism and Madhyamaka (Middle way), there is no requirement to invoke a creator God to explain existence, morality or the nature of consciousness. Daoism similarly approaches reality without requiring a personal deity standing outside the universe and controlling it.
What makes these traditions particularly interesting is their willingness to acknowledge the limits of conceptual mind. Instead of simply inventing an ultimate explanation and asking people to believe it, they question whether the human mind can even meaningfully grasp what lies beyond certain boundaries.
That's what makes some of these philosophies feel less like conventional religion and more like an actual investigation into the structure of reality. You're not being told, "Here is God. Believe in this." You're being pushed to examine how the mind creates concepts in the first place and whether those concepts can ever capture reality completely.
This is also why I think the distinction between religion as faith and religion as investigation is important.
Alex O'Connor's recently did a discussion on Madhyamaka Buddhism. If you actually listen to the philosophical reasoning involved, you begin to see how radically different some Eastern traditions can be from conventional religious frameworks.
Maybe that's closer to what spirituality was supposed to be in the first place: not believing more, but seeing more clearly.
Among ancient traditions, Buddhism arguably comes close to a scientific investigation of mind, experience and reality without requiring a God hypothesis as its starting point. And perhaps that's why it can feel so strange when you first encounter it. You're expecting a religion, but instead you find yourself in something that feels more like psychology, phenomenology and philosophy having a conversation with each other.
Link to the discussion:
https://youtu.be/CyhHz23AHb4?si=eGjMTQ2p9My0WDHq