After the Buddha achieved his own awakening, his first teaching covered the core teachings that he would expand on for the next 45 years of his life.
Central to his ongoing teaching and direction was the Four (Noble) Truths – the truth of the world, the truth of ourselves and the truth of our view of the world around us. The truth of how to start down the path to awakening ourselves through our understanding of ourselves and where suffering is created, and how to minimize and eliminate it from our lives and mind.
The Four Truths:
First Truth: To be alive comes with conditions which create dukkha (unsatisfactory situations that cause unhappiness and suffering).
Second Truth: Dukkha is furthermore caused from our own actions, viewpoints and clinging to our thoughts and perceptions. These are all of our making in our mind, and they have no lasting nature.
Third Truth: It is possible to let go of dukkha by changing our view and arising thoughts, to release our attachments, within our lifetimes and be liberated from our suffering.
Fourth Truth: The ability to overcome dukkha can be aided through living our lives with a certain structure, discipline and practices that will help to uncover the arising mind. These sets of practices are referred to as the eightfold path, and is the way towards understanding that liberation for yourself.