We can choose to be buddhas or ordinary beings. What I mean is that when we recognize the nature of mind just as it is, pure and stainless, we are buddhas and we manifest inconceivable beneficial activity without karma. But when we fall under the sway of duality, the perceived separation of subject and object, we are ordinary beings and our experience is heavy and materialistic, and we create lots of karma that is the source of endless suffering. This choice lies before us. In Mahayoga, our natural state that we wish to recognize is portrayed as a wisdom deity or divine being.
Deity is synonymous with bodhicitta.
Deity is a pure state of being that is beyond duality and not constricted by the forces of clinging and grasping. Since all beings have mind, they also have the nature of mind. Therefore, all beings are divine because their nature is pure. However, their pure nature is not manifest. It is like butter in milk.