Teresa was born in Spain, near Avila. Even in her childhood, she took much pleasure in the study of saints’ lives, and she used to delight in spending times of contemplation, repeating over and over, “For ever, for ever, for ever, for ever, they shall see God.”

In her autobiography, Teresa tells that following her mother’s death, she became quite worldly. To offset this, her father placed her in an Augustinian convent to be educated, but serious illness ended her studies. During convalescence, she determined to enter the religious life and, though opposed by her father, she became a postulant at a Carmelite convent. Again, illness forced her to return home, but after three years, she returned to the convent.

Her prayer life during this period was difficult. She wrote: “I don’t know what heavy penance could have come to mind that I would not have gladly and frequently undertaken rather than recollect myself in the practice of prayer.” This early difficult experience would shape her later writings on prayer, in which she insisted that the spiritual life cannot be grounded in feelings and consolations.

In time, frustrated by the laxity of life in her community, Teresa set out to establish a reformed Carmelite order of “discalced” religious, who wore sandals or went barefoot. Despite many setbacks, she traveled for 25 years throughout Spain. Energetic, practical, and efficient, as well as being a mystic and ascetic, she established 17 convents of Reformed Carmelites. Even imprisonment did not deter her. Her younger contemporary John of the Cross became a close personal and spiritual friend.

Her sisters urged her to write down some of her teachings on prayer for them, which is how we came to have her works The Interior Castle and The Way of Perfection. Many people at the time felt that mental prayer (as opposed to reciting the vocal prayer of the liturgy) was too difficult and too dangerous for women, but Teresa insisted that “Mental prayer is nothing else than an intimate sharing between friends. It means taking time frequently to be alone with him whom we know loves us.”

Despite the demands of her administrative and missionary work, Teresa found time to write the numerous letters that give us rare insights into her personality and concerns. Her extensive correspondence often kept her awake at night until 3:00 in the morning, after which she would awaken at 5:00 for morning prayer with the community. Teresa found writing to be burdensome, and often protested that she would be much happier spinning or working in the kitchen. Once she sat down to write, however, she was eloquent and efficient. Her great work The Interior Castle was written in less than two months.

Her death in 1582, following two years of illness, was peaceful. Her last sight was of the Sacrament, brought for her comfort; her last words, “O my Lord! Now is the time that we may see each other.”