Theresa of Avila has been known as a mystic and a reformer, due to her exceptional inner experience and the successful re-establishment of the bare-foot Carmelites. Theresa's life, rich in spiritual experience and life satisfaction, was just a result of her efforts aimed at gaining more life than it was offered her by the Spanish society, the Church and the Carmelite Order of her time. Theresa's activity on the other hand was just an expression of her rich and content life. But, in order to attain as much life as she needed to be happy, Theresa had to change her and her time's understanding of God. She had found that God is nothing more and nothing less than the source of life. She had replaced the image of God the Ruler, inherited from the Christian tradition, and improved the image of God the Father projected by Jesus of Bethlehem. Theresa's experience and discoveries are welcome by all those who consider the concept of God the Father slightly poor in meaning.