St Teresa seems to have been a woman of iron will. Born in 1515 at Avila in Spain Teresa joined the Carmelites in 1533. This was the time of the Reformation and Europe was in turmoil with the new teachings of the reformers. However Spain was largely untouched by the reformation but Teresa would have been aware of what was going on.
For the first years of her life as a nun Teresa led a strict life, full of acts of penance and fasting. After having profound mystical experiences of God, Teresa decided to found a community of her own which would lead a primitive life and "follow the way of perfection." By this she meant a life of contemplation dedicated to the love of Christ.
Her writings are still rated among the great Christian classics. "The Interior Castle" is her great work. Teresa gives practical advice for beginners regarding the early struggles and the temptation to turn back and give up.
If a person wanted to seriously improve their prayer life there would be no better place to start. Not only did she become a saint but she was given the honour of Doctor in the Church. Out of 33 saints who have this title, St Teresa is one of only three women.