Maitreya is a transcendent bodhisattva named as the universal buddha of a future time. The name is taken from the Sanskrit maitri (in Pali, metta), which means "loving kindness." In Mahayana Buddhism, Maitreya is the embodiment of all-encompassing love.
Maitreya is depicted in Buddhist art in many ways. "Classical" portrayals often show him seated, as in a chair, with his feet on the ground (see, for example, the Leshan Buddha). He is also portrayed standing. As a bodhisattva he dresses as royalty; as a buddha, he dresses as a monk. He is said to reside in the Tushita heaven, which is part of the Deva Realm of the Kamadhatu (Desire Realm, which is the world depicted in the Bhavachakra).
In China, Maitreya is identified as the "laughing buddha," Pu-tai, who is the fat, jolly portrayal of Buddha that emerged from 10th century Chinese folklore.
Origins of Maitreya
Maitreya makes his first appearance in Buddhist scriptures in the Cakkavatti Sutta of the Pali Tipitika (Digha Nikaya 26). In this sutta, the Buddha spoke of a future time in which the dharma is entirely forgotten. Eventually, "Another Buddha -- Metteyya (Maitreya) -- will gain Awakening, his monastic Sangha numbering in the thousands," the Buddha said.
This is the only time the historical Buddha is recorded as mentioning Maitreya. From this simple comment arose one of the most important figures of Buddhist iconography.
In the early first millennium CE, Mahayana Buddhism developed Maitreya further, giving him a history and specific attributes. The Indian scholar Asanga (ca. 4th century CE), a co-founder of the Yogacara school of Buddhism, is particularly associated with Maitreya teachings.
Note that some scholars think attributes assigned to Maitreya were borrowed from Mithra, the Persian god of light and truth.
The Cakkavatti Sutta speaks of a distant time in which all skillfulness in dharma practice is lost and mankind will war with itself. A few people will take shelter in the wilderness, and when all others are slaughtered these few will emerge and seek to live virtuously. Then Maitreya will be born among them.
After this, various Mahayana traditions weave a story that closely resembles the life of the historical Buddha. Maitreya will leave the Tushita heaven and be born in the human realm as a prince. As an adult, he will leave his wives and palaces and seek enlightenment; he will sit in meditation until he is fully awakened. He will teach the dharma exactly as other buddhas have taught it.
Before getting too caught up in anticipation, it's important to understand that in most schools of Buddhism linear time is an illusion (see "About Time: What Does Buddhism Teach About Time?"). This makes speaking of a literal future a bit problematic, since "future" is an illusion. From this perspective, it would be a huge mistake to think of Maitreya as a messianic figure who will come in the future to save mankind.
Cults of Maitreya
One of the central teachings of the Buddha is that there is no one "out there" who will save us; we liberate ourselves by our own efforts. But the human craving for someone to come along, fix our messes and make us happy is powerfully strong. Over the centuries many have made Maitreya into a messianic figure who will change the world. Here are just a few examples:
A 6th century Chinese monk named Faqing proclaimed himself to be the new buddha, Maitreya, and drew many followers. Unfortunately, Faqing appears to have been a psychopath, persuading his followers to become bodhisattvas by killing people.
A 19th century spiritualist movement called Theosophy (see "Henry Steel Orcott's Unlikely Life") promoted the idea that Maitreya, a world redeemer, would soon come to lead mankind out of darkness. His failure to appear was a major setback for the movement.
The late L. Ron Hubbard, founder of Scientology, claimed to be an incarnation of Maitreya (using the Sanskrit spelling, Mettayya). Hubbard even managed to patch together some bogus scripture to " prove" it.
An organization called Share International teaches that Maitreya, the World Teacher, has been living in London since the 1970s and will gradually make himself known. In 2010 Share's founder, Benjamin Creme, announced that Maitreya had been interviewed on American television and had been seen by millions. Creme failed to reveal what channel hosted the interview, however.
People picking up on Creme's claim have decided Maitreya is the antichrist. Views differ as to whether this is a good or bad thing.
And so on. It must be emphasized that even if Maitreya is to appear in a literal future, this is not supposed to happen until the dharma is completely lost. And then Maitreya will teach the dharma exactly as it has been taught before. Since the dharma is available in the world today, there's no literal reason for Maitreya to appear. There's nothing he can give us that we don't have already.