Buddhism - Is it a religion?

Because supernatural or transcendental is natural in buddhism. We can found supernatural in many sutta, vinaya, even though abhidhamma of tipitaka (pali), because there are many possible cases of supernatural by logic, causes and effects.

However, all supernatural is natural in buddhism by 3 characterizes: "when arising exit, then vanishing exit, too", paṭiccasamuppāda. So, supernatural is not important in buddhism.

Therefore, in buddhism, we don't try to debate about next life, heaven, or supernatural. We do not deny any possible theories, in causes and effects logic. Then we develop consciousness to cope every possible situations, not cope just some situations that we have seen. We try to avoid every possible suffering, by logic or theory, to make sure suffering will never return anymore, although we never meet that possible suffering and possible situation.

https://en.wikipedia.org/wiki/Religion

Buddhism is a religion. As in any religion one must have faith to advance. Faith is important in any religion.

Of course it is. The word "religion" comes from the Latin "religare" which literally means "to bind". To be a religious person is to take on a set of beliefs, bonds, obligations, and laws so as to arrive at some sort of understanding or union with the divine. I'd go so far as to say that the word "religion" is an almost perfect translation of the Sanskrit word "yoga" which means "yoking" such as when you place an animal in harness so as to be led. Both imply that the adept is submitting their will to a spiritual vector that is not of their own creation. They are relinquishing their own way-making for a path set down by those who have gone before.

To undertake the Buddhist path is to take on a set of precepts and training principles so as to understand, with direct knowledge, the experiences enjoyed by those Buddhas and other enlightened persons who have gone before you. To practice Buddhism is to put your trust in the training even when it asks for things that are outside your comfort zone and current level of understanding. To be a Buddhist is to be a person of faith - both in the efficacy of the Dharma and your ability to realize it.

Buddha is a 'dhamma', which means a set of knowledges, practises, path & realisations that support the mind to be free from suffering. The word 'dhamma' means 'that which supports'.

Therefore, Buddhism is not a religion & is not 'yoga' or 'binding'. In his 1st sermon (SN 56.11), the Buddha taught to not be bound ('yogo') or 'devoted to'.

The Buddha taught to not cling to the teachings (MN 22); not to cling to him (SN 22.87) or have blind faith in him (MN 38; AN 3.65). The enlightened practitioner is 'independent' (MN 56).

The Buddha called his path of practise 'the holy way of life' ('brahmacariyaṃ'; MN 29 & 30) therefore it is certainly a way of life rather than a religion.

There is nothing 'supernatural' in Buddhism. Everything is natural (dhatu; MN 115; MN 140), including phenomena such as 'supernormal psychic powers'.

The 'gods' in Buddhism are merely people; i..e, the rich, powerful or psychic mystics from other paths. There are no gods, apart from people, such as Sakka, king of the gods, who lived in a palace with many sexy nymphs (MN 37). The gods rule the people (SN 11.5). That is why in Thailand, the king is considered a 'god' or reincarnation of the Hindu Vishnu.

However, in countries such as Thailand, Sri Lanka & Tibet, Buddhism is a religion for the common people called 'puthujjana', where the common people believe in spirits, spirits of ancestors, ghosts, gods in the sky, gods in the trees, angels, reincarnation & other superstitious 'religious' things.

This photo is of people in Thailand worshiping a Hindu god & spirit house.

It depend on what you mean by the word religion.

the belief in and worship of a superhuman controlling power, especially a personal God or gods

If you take above definition, Buddhism is not a religion.