Bodhidharma: Even if a buddha or bodhisattva should suddenly appear before you, there's no need for reverence. This mind of ours is empty and contains no such form. Those who hold onto appearances are devils. They fall from the Path. Why worship illusions born of the mind? . . . The basic nature of a buddha has no such form. Keep this in mind, even if something unusual should appear. Don't embrace it, and don't fear it, and don't doubt that your mind is basically pure. . . . Also at the appearance of spirits, demons, or divine beings, conceive neither respect nor fear. Your mind is basically empty. All appearances are illusions. Don't hold on to appearances. If you envision a buddha, a dharma, or a bodhisattva and conceive respect for them, you relegate yourself to the realm of mortals. If you seek direct understanding, don't hold on to any appearance whatsoever, and you'll succeed. . . . The sutras say, "That which is free of all form is the buddha."
Disciple: But why shouldn't we worship buddhas and bodhisattvas? Bodhidharma: Devils and demons possess the power of manifestation. They can create the appearance of bodhisattvas in all sorts of guises. But they're false. None of them are buddhas. The buddha is your own mind. Don't misdirect your worship.
Disciple: But the Bathhouse Sutra says, "By contributing to the bathing of monks, people receive limitless blessings." This would appear to be an instance of external practice achieving merit. How does this relate to beholding the mind?
Bodhidharma: . . . Our true buddha-nature has no shape. And the dust of affliction has no form. How can people use ordinary water to wash an intangible body? It won't work. . . . To clean such a body you have to behold it. Once impurities and filth arise from desire, they multiply until they cover you inside and out. But if you try to wash this body of yours, you'll have to scrub until it's nearly gone before it's clean.
Source: The Zen Teaching of Bodhidharma