For very human reasons, people wish to know if Zen is a religion.
To me, the answer depends on whether we are discussing Zen as an idea, Zen as an individual practice, or Zen as a culture. It also depends on who you are as a person and what your ‘ingredients’ would have you prefer.
Many of its practitioners do not consider Zen a form of worship. After all, when we see through to the bottom of things there is no reason to worship. We see that nothing needs to be added to this reality, and no supernatural force needs to be appeased. No rewards are earned by steady practice, there is no tally of good deeds done, and there is nothing mystical to manage.
Whether any supernatural rewards and beings exist in the first place is inconsequential to Zen: none of them are required by you to fully experience this moment, right now.
At its core, Zen is sitting still and letting the mind become aware of the essential world as it is. Nothing needs to be added to that world. In fact by adding something, such as the worship of the Buddha or the belief in a supernatural reward for good actions, we might be adding hindrances that work against our basic ability to recognize the fundamental point: reality is the wonderful This.
Zen tends to view the Buddha as a human. That is, a human like us who had sensations and thought and a body and brain like we have. He was remarkable because of the effort he expended to realize, his eventual success in doing so, and his subsequent compassion for all things. Zen stresses that we all have the potential for enlightenment, which we can access by sitting quietly and releasing our attachment to forms. In short, each of us has everything we need to accomplish what the Buddha did. No worship is required.
Humans love to understand the world by using labels, which is our way of partitioning off this vast interconnected reality into small bits that make sense to our brains. To classify Zen, therefore, people might feel a need to label it a religion. Given one’s personal ingredients, one might also have the desire to practice it as a religion, and even call oneself religious. It is not at all necessary, but many do so.
Remember, in its purest form Zen is a method of awareness. It is a tool that brings clarity to our flurry of thoughts and allows us to see the absolute world of which we are seamlessly a part. It does not contend with religion, which is why Zen can be practiced alongside a set of religious beliefs such as Christianity.
The perpetuation of Zen’s method, history, and culture does take on ritualistic forms. Zen centers and monasteries can seem highly ritualized. Through long tradition, a member’s time and actions are often constrained, a strong commitment is helpful, and certain postures are stressed. Bells are rung. Chanting occurs. Incense might be burned. Special clothes are worn. Meals are prepared and cleaned up in specific ways. History and hierarchy are respected.
But none of this is essential for attaining awareness. The structure is there to help humans establish a path to realization and then learn to work with that realization under a variety of circumstances. It is also there to secure an approved transmission of the Dharma, the history of which has been maintained since the time of the Buddha.
It is said that the tools for enlightenment are like a raft that one uses to cross a great river. Once you’ve reached the other side, the raft should not be carried with you. Even the concept of ‘enlightenment’ should be left behind as one moves in the world with realization of the absolute.
Each person, however, has his/her own ingredients, and sometimes those ingredients crave worship. If your ingredients respond well to striking bells and chanting sutras, that is fine as long as you are diligently working to cross the river. But it is important that the traveller does not marvel too much at the raft and forgets to advance to the other shore.
