Pope Benedict XVI , with that very sensus Ecclesiae that characterised his theological and pastoral Magisterium to the end of his pontificate, introduces us in this volume to the heart of the mystery of the Church. The simplicity and transparency of his immense embrace of the world at the moment of his leaving the government of the Church was, in a certain sense, the concluding act of his teaching about faith and communion. By considering the teachings of Benedict XVI as a whole we can clearly see how he has delineated a true and proper systematic theology of love.