The Buddha taught that there is nothing in this mundane world but suffering. Life is full of pain. Nothing can be relied upon, because everything is temporary. That is the First Noble Truth of Suffering. We must recognize this as it is, and determine to be liberated from this ocean of misery. The cause of our suffering, the Buddha explained, is our negative deeds, whether physical, vocal, or mental. These deeds leave habitual traces in our mind. These traces, in turn, produce commensurate experiences for us in the future. This chain of cause and effect is called karma. At the root of karma is the duality of deluded mind. As long as we remain in the never-ending cycle of lives created by negative causes and effects, and as long as our minds are ignorant of the truth, we keep wandering endlessly and aimlessly around samsara—cyclic existence. This is the Second Noble Truth. We must recognize it and stop engaging in deeds that will cause us future pain.
The Buddha then taught that there is a state where all suffering ends. That state is enlightenment or Buddhahood. This is the state where we realize the true nature of our mind and the universe, as it is—nondual and free from all trace of concepts or emotions. This is the Third Noble Truth. We must attain it.
Then the Buddha taught something radical: there is a path that leads to enlightenment. Buddhists call it the Eightfold Noble Path. It gives us the tools—right view, right thought, right speech, right action, right livelihood, right effort, right mindfulness, and right concentration— to purify our heart and attain Buddhahood. If we pursue the path of positive thoughts and deeds, we will improve the quality of our existence. And if we realize perfect wisdom, we will attain freedom from suffering and Buddhahood, the cessation of cyclic existence. This is the Fourth Noble Truth. We must apply it to our hearts.
Source: The Heart of Unconditional Love