On 7 October 2012, Pope Benedict XVI declared St John of Avila a Doctor of the Church, making him the thirty-fourth Saint to have been given this title. St John of Avila was a diocesan priest in sixteenth century Spain and has been honoured there since 1946 as the patron Saint of diocesan priests. Amongst St John of Avila's disciples were St Teresa of Avila, St Francis Borgia, St John of God, and Venerable Anne of the Cross. In fact, St Teresa of Avila, also a Doctor of the Church, had the account of her life and mystical experiences confirmed as authentic by St John of Avila. This account is what we know today as The Book of Her Life. St John of Avila's teaching was extremely beneficial in his own time, and is just as relevant today, in a time when we are all called to be strong Christian witnesses for the new evangelisation. The most effective way we can respond to this call is to enter into a deep and intimate relationship with God. St John of Avila is a Saint for all people and all times; Pope Benedict XVI has called him a 'pioneer in pointing to the universal call to holiness'. St John of Avila is a wise mentor for all those who desire to grow in friendship with God. In simple and accessible language, this book sets forth much of the practical advice which St John of Avila gives in his spiritual work Audi Filia and various letters to those whose spiritual life he directed. In this short book, Dr Oliver focuses on the soul's journey in the life of prayer, how to overcome particular struggles and temptations, and how to recognise deceitful tactics of the devil. She clearly explains the fundamental aspects of the supernatural organism, the graced soul on the road to union with God. And she takes great care to help the reader understand how to differentiate between spiritual experiences which are not essential for advancing in holiness and that which is necessary for growth in the spiritual life. This little book is an essential resource for anyone seeking a deeper and more intimate union with the loving and merciful Lord; for He is always ready to shower His children with the riches of His merciful love.