All the Buddha’s teachings center around the Four Noble Truths, the formula into which he compressed the essence of his realization.
The First Noble Truth teaches that life involves suffering. It is impossible to live without experiencing some kind of discomfort or stress. Possessing bodies, we have to endure sickness, injury, fatigue, old age, and death. In our minds we experience loneliness, frustration, fear, embarrassment, disappointment, and anger. We seek fulfillment in the pleasures of the senses, but always come away unsatisfied.
The Second Noble Truth holds that all suffering is caused by selfish craving. Craving in turn is rooted in ignorance, a distorted understanding of ourselves and the world.
The Third Noble Truth states that by eliminating ignorance and craving we can overcome suffering and thereby attain true happiness and peace.
The Fourth Noble Truth is the path to freedom from suffering, namely, The Noble Eightfold Path.
