The Way of Perfection, by Teresa of Avila (1515-1582)
Explains the meaning of mental prayer.
When you approach God, then, try to think and realize Whom you are about to address and continue to do so while you are addressing Him. If we had a thousand lives, we should never fully understand how this Lord merits that we behave toward Him, before Whom even the angels tremble. He orders all things and He can do all things: with Him to will is to perform. It will be right, then, daughters, for us to endeavour to rejoice in these wondrous qualities of our Spouse and to know Whom we have wedded and what our lives should be. Why, God save us, when a woman in this world is about to marry, she knows beforehand whom she is to marry, what sort of a person he is and what property he possesses. Shall not we, then, who are already betrothed, think about our Spouse, before we are wedded to Him and He takes us home to be with Him? If these thoughts are not forbidden to those who are betrothed to men on earth, how can we be forbidden to discover Who this Man is, Who is His Father, what is the country to which He will take me, what are the riches with which He promises to endow me, what is His rank, how I can best make Him happy, what I can do that will give Him pleasure, and how I can bring my rank into line with His. If a woman is to be happy in her marriage, it is just those things that she is advised to see about, even though her husband be a man of very low station.
- Chapter 22
(Keep in mind that she is writing to sisters in a cloistered contemplative order.)