To acquire and preserve this precious virtue of devotion, which of itself disposes us for the practice of all other virtues, we must watch over ourselves with special vigilance. So little suffices to make us lose this delicate virtue. Frivolous conversations, excessive mirth, immoderate indulgence at table, slight anger, unnecessary disputes, curiosity and eagerness to see and hear what does not concern us, besides many similar faults, while not grave in themselves; weaken, and sometimes destroy, the spirit of devotion. To preserve the intense heat communicated to it by the fire, iron must be kept continually in the furnace-----or, at least, it must seldom be withdrawn. Otherwise it will quickly resume its former temperature. In like manner, if we would keep our hearts inflamed with the fire of devotion, we must remain closely united to God by the practices we have mentioned.
--Louis de Granada, The Sinner's Guide
