One of the important aspects of teaching in Buddhism is one on Buddha Nature. Actually this is more toward Mahayana, but it’s there in Theravada too but not much emphasized. The idea of Buddha Nature is that every sentient being has the seed of eventually becoming a Buddha inside of it. When the seed is fully realized, then the being becomes an enlightened Buddha.
This teaching is what gives meaning to the practice of bodhisattvas. For those who are new to Buddhism, bodhisattvas are beings who are committed to becoming a Buddha in order for them to be fully able to help ferry sentient beings across the ocean of suffering to the shore of Liberation. The Buddha Nature teaching tells us that it is possible for everyone to become a bodhisattva and a Buddha. This is not only limited to human beings, but since a human being is but one form that a sentient being can take and since a human being used to be a countless number of animals and other forms of being in their previous lives, an animal can also become a Buddha. Even Shakyamuni Buddha himself used to be born in all animal forms, so who knows that the lowly insect in front of you might actually be a bodhisattva. In fact the insect actually has the potential to become a bodhisattva and the Buddha. This is the gist of the teaching on Buddha Nature.
There is a passage in the Tripitaka that the “original mind” of all of us is essentially pure, and it is only because of adventitious defilements that the original mind become cloudy and thus is subject of wandering around in samsara. This can well be a point for reflection in meditative practice. When the defilements and their root are gone, and the root of all defilements is avidya, or the ignorance of the fundamental nature of reality, then the original mind shows itself forth in its primordial purity. That is the goal of practice, the showing forth of the original mind constitutes entering into nirvana, or the state of totally extinguishing all causes of suffering which lead one to wander in samsara.
But how can one get rid of avidya? That is the subject matter of the Buddha’s 45-year teaching career and countless number of texts and commentaries. The trick is that the original mind should not be thought of as something existing objectively for there to be cleaned. The original mind is not a crystal ball that you can clean up. Talks about the original mind being “pure” and adventitiously “polluted” by the “defilements” are only metaphors. At this level we can rely only on metaphors because language fails us. The reason is that it is the very nature of language itself that is part of the root cause of suffering itself. But we can get very far into this and easily get lost, so enough of this for now.
In any case, the original mind shows that there is Buddha Nature in all of us. When you come to Buddha Nature, then it can be said that you come to who you yourself really is from the beginning. Total disclosing, no concealment whatsoever. This is what the Zen masters say when they tell you to look for “your own face before your father and mother got married” …
(Actually I have written a post on this topic before, but the content is not the same, I think.)