The world is filled with suffering. We think the wrong things, do the wrong acts, perform kindness without a good return, not understanding why things have changed, and so forth. We experience suffering all the time because we lack an understanding of the karmic principle.
The Buddha taught the Four Noble Truths: the truth of suffering, the truth of the origin of suffering, the truth of cessation, and the truth of the path – explain the working between karma and suffering, as well as the way to eradicate suffering. Where does suffering come from? Ego. How? The improper views that we’ve been too habituated with for lifetimes. The negative causes accumulated ripen into the result of suffering.
All the suffering originates from the fabrication of the mind. When sentient beings are taking rebirth, they are repelled by their karma and desires in the cyclic existence. When fertilization is taking place, the consciousness of a being enters fusion where the karmic memory drive grows and fosters. Then, by sequence, the six sensory faculties develop along with their respective karmic memory drive. Every drive is different as well as causes and conditions. When the causes and conditions join to take effect, a human body comes to the formation. This body is an entity of collective karmic memories.
How do sentient beings come to death? Metabolism is the biochemical reason for cell growth and reproduction. One's life constitutes of several stages. When the karmic memory drive of this life comes to the end, another drive will replace. This is rebirth. Living and dying is the replacement of the karmic memory drive. Then, where is this drive? It is inside our subconsciousness, or, the eighth consciousness in Buddhism.
The eighth consciousness is the storehouse of karmic memories. Everyone has it and it contains lifetimes of memories and actions. The interconnected network is stored within. As a matter of fact, the universe is a gigantic field of the eighth consciousness. All sentient beings are encompassed within. If we commit many virtuous acts this life, we’d take rebirth to the upper realms. On the contrary, if we engage in non-virtuous acts, we’d be lured by negative karma to take rebirth in the three lower realms.