Water comes from its own source which is God. And since God desires to do so ... God produces this delight with the greatest peace and quite and sweetness in the very interior part of ourselves. I don't know from where or how, nor is that happiness and delight experienced, as are earthly consolations, in the heart. I mean there is no simliarity at the beginning, for afterward the delight fills everything; this water overflows through all the dwelling places and faculties until reaching the body. ... It begins in God and ends in ourselves.

- Saint Teresa of Avila
from "Interior Castle"