Much of The Way of Perfection concerns how the highest form of prayer is to take the most basic vocal prayers–particularly the Pater Noster and the Angelic Salutation–and to meditate carefully on their words. St. Teresa de Jesus devotes at least a chapter to each of the phrases in the Lord’s Prayer, though she does not offer a similar treatment of the Ave Maria. She refers to them as being “books” from which we can learn a great deal if we study them carefully. And, if they are all we have, they’re all we need.
“No one will be able to take from you these books (the Our Father and the Hail Mary), and if you are eager to learn you won’t need anything else provided you are humble” (Way of Perfection, Ch. 21, para. 4).
It reminds me of the conversion of Fr. John Corapi, SOLT–when he was at “rock bottom,” living on the streets of LA following release from a year in a VA mental hospital, his mother sent him a prayer card. It had the “Hail Mary” on the back. He was so far from the Church that he had forgotten the “Hail Mary.” He read that card and prayed one “Hail Mary” devoutly, every day.
Or Thomas Howard, who says somewhere in On Being Catholic, “We cannot say so much as one ‘Hail Mary’ without bringing down all of glory on our heads.”