St. Teresa of Avila was born Teresa Sanchez Cepeda Davila y Ahumada, in Avila, Spain, in 1515. Her parents were Jewish merchants who had converted to Christianity under King Ferdinand and Queen Isabella. 

When she was young, Teresa often thought of God and sainthood; she and her brother, Rodrigo, ran away once in an attempt to become martyrs in a Muslim country, but they were sent home by relatives. 

Teresa’s mother died when she was 14. The loss was hard on Teresa, but it drove her to a more spiritual relationship with the Virgin Mary. While she embraced her spiritual mother, Teresa began to care about her appearance, and became more interested in reading the popular literature of the day than religious texts, so her father sent her to live in a convent of Augustinian nuns. 

In her second year there, Teresa was forced to leave because of her health, but she had already determined that her best course to salvation was to forsake marriage and earthly pleasures, and join the Carmelites. 

Despite her father’s objections, Teresa became a Carmelite at the age of 20, but as her health worsened, she had to return home, where she suffered serious pain for another two years, before being able to return to her monastery. 

While she was ill, Teresa developed a dedicated spiritual prayer life, but as she regained her health, her deep connection to God lapsed. For 20 years, she served as an obedient nun, but without the deep spirituality she had once had. 

Around the age of 40, Teresa received visions from God, and experienced changes in her soul, which brought her back to contemplative mental prayer. Her autobiography, written in 1565, details some of her experiences. 

With this renewed prayer life, Teresa was instrumental in reforms for the Carmelite Order following the Council of Trent. In an effort to return the order to their simple, austere monasticism, based in silence and solitude, she founded the Order of Discalced Carmelites (discalced means barefoot, symbolizing the simplicity of their order). During her life, she faced a great deal of backlash for her reforms, but also saw the founding of 30 new monasteries. 

In 1582, Teresa’s health failed one last time. She welcomed her fate as God’s final call to bring her home. She died on Oct. 15, 1582, and was canonized on March 22, 1622. 

In 1970, Pope St. Paul VI proclaimed St. Teresa a Doctor of the Church.