Deity yoga is a central practice of Tibetan Buddhism, with the term “deity” referring to enlightened beings. Amida Buddha is one of many such meditation deities utilized for the sake of realizing one’s Buddha-nature:
The purpose of Deity yoga is to bring the meditator to the realization that the yidam or meditation deity and the practitioner are in essence the same, that they are non-dual (advaya). According to John Powers. “Deity yoga is a technique for becoming progressively more familiar with the thoughts and deeds of a buddha, until the state of buddhahood is actualized through repeated practice.”
According to Gyatrul Rinpoche, the point of this practice is to “understand your buddha nature, which is the very essence of your being” and is “intrinsically present” in all beings. The fact that the deity is a reflection of qualities already inherent in the practitioner is what makes this practice different than mere deluded or wishful thinking.
Deity yoga, then, is a practice which helps us identify with a particular fully enlightened being or Buddha in order to realize our innate Buddha nature. Using visualisation, chanting, mantra recitation, and meditation, we focus upon a particular deity and in many practices visualize ourselves as that deity, non-dual with them…
The deity mirrors to us our true enlightened nature. As our practice deepens, and we reach an ever closer identification/relationship with the deity, delusion and obscuration are revealed as illusory, and the energies of deluded mind transform into their non-dual, naturally enlightened qualities.
His Holiness the Dalai Lama has said, “In brief, the body of a Buddha is attained through meditating on it.”
Like in Zen Buddhism, the purpose of Pure Land practice in deity yoga is to realize Amida Buddha as our True Self:
Thine own consciousness, shining, void, and inseparable from the Great Body of Radiance, hath no birth, nor death, and is the Immutable Light-Buddha Amitabha.
This is the Dalai Lama blessing a statue of Amida Buddha:
Amitabha Mantra (A Mi De Wa Hrih)