If the doors of perception were cleansed, everything would appear as it is—Infinite. But the doors of perception are hung with the cobwebs of thought: prejudice, cowardice, sloth. Eternity is with us, inviting our contemplation perpetually, but we are too frightened, lazy and suspicious to respond: too arrogant to still our thought, and let divine sensation have its way. It needs industry and good will if we would make that transition: for the process involves a veritable spring-cleaning of the soul, a turning-out and rearrangement of our mental furniture, a wide opening of closed windows, that the notes of the wild birds beyond our garden may come to us fully charged with wonder and freshness, and drown with their music the noise within.
Source: Practical Mysticism