Here is a prayer from 14th century Italian author Catherine of Siena (1347 – 1386):

“You, O eternal Trinity, are a deep sea, into which the more I enter the more I find, and the more I find the more I seek . . . O eternal Godhead, what more could you give me than yourself? You are the fire that ever burns without being consumed; you consume in your heat all the soul’s self-love; you are the fire which takes away cold; with your light you illuminate me so that I may know all your truth. Amen”