The Four Noble Truths and The Eightfold Path.
Seven weeks after the Buddha reached enlightenment, at a place called Sarnath, in India, he gave his first teaching. This is referred to as setting the wheel of Dharma in motion. Here he first spoke of the Four Noble Truths.
# To live means to suffer, because the human nature is not perfect and neither is the world we live in. During our lifetime, we inevitably have to endure physical suffering such as pain, sickness, injury, tiredness, old age, and eventually death; and we have to endure psychological suffering like sadness, fear, frustration, disappointment, and depression. The Pali word, the Buddha's language, for suffering is dukkha. The Buddha said there are three kinds of dukkha. The first two are inevitable and the third is optional.
The first is dukkha-dukkha, or ordinary suffering. This include what the Buddha calls the three great teachers: sickness, old age and death, and the loss of a loved one.
The second is viparinama-dukkha. In life even though we are happy, we know that our happiness won t last forever. This awareness that life will no always be this way often brings us sadness, and explains why the Buddha says that even happiness is dukkha. .
The third is samkhara-dukkha. This is the suffering of conditioned states. The Buddha believes that the thoughts that often pass through our heads can bring us much suffering. Corrado Pensa, a Buddhist teacher warns, "Be careful when you enter your mind, it may lead you behind enemy lines." This is the one dukkha that we have some control over.
Although there are different degrees of suffering and there are also positive experiences in life that we perceive as the opposite of suffering, such as ease, comfort and happiness, life in its totality is imperfect and incomplete, because our world is subject to impermanence. This means we are never able to keep permanently what we strive for, and just as happy moments pass by, we ourselves and our loved ones will also pass away one day.