The Four Noble Truths comprise the core ideas of Buddhism. They do not merely impact Buddhism, they are Buddhism. Everything in Buddhism springs from these tenets. If you can fully understand and embody the four truths, there is nothing else needed to attain enlightenment. Such is the nature of the Four Noble Truths.
Buddhism
the answer is four.
Mahayana is the only proper Japanese buddhism
Christianity, Islam, Buddhism, Hinduism
Astangamarga
Buddhism is founded on the teachings of the Buddha, in particular the Four Noble Truths and the eightfold path.
The major belief (or teachings) of Buddhism is the Four Noble Truths. The major practice of Buddhism is the Five Noble Precepts.
Buddhism
The Four Noble Truths.
The four noble truths are associated with Buddhism. They are considered the foundation of the Buddha's teachings and outline the nature of suffering and the path to its cessation.
Buddhism grew from the teachings of Siddhartha Gautam, the Buddha (hence BUDDHism). Some of his main teachings were karma, the Four Noble Truths and the Eightfold Paths.