Saint Teresa is among the most important figures of all time for Catholic spirituality. Her works - especially the four best known (The Life, The Way of Perfection, The Mansions, and The Foundations) - together with her more historical works, contain a doctrine that encompasses the whole of the spiritual life, from the first steps right up to intimacy with God at the center of the Interior Castle.
Her Letters show her occupied with a great variety of everyday problems. Her doctrine on the unity of the soul with God (a doctrine which was intimately lived by her) follows the Carmelite tradition which had preceded her and to which she herself contributed in such a notable way, enriching it as well as passing the tradition on, not only to her spiritual sons and daughters but also to the whole Church which she served so unsparingly. When she was dying, her one joy was to be able to affirm that "I die a daughter of the Church". 1970, the Church gave her the title she had long held in the popular mind: Doctor of the Church. She and St. Catherine of Siena were the first women so honored.
St. Teresa is the patron saint of Headache sufferers. Her symbol is a heart, an arrow, and a book. She was canonized in 1622.