Our task is not only to develop the perennial teaching of the Catholic Church on prayer as comprehensively as possible, but also to familiarize ourselves with what one would like to call the art of prayer. For, as in all other practical activities, it is not enough to know what it is, as one also needs to know how to pray. In other words, theory is insufficient, practiceis necessary, a certain art, with its own methods and practical skills. We shall endeavour to derive teachings on prayer and the art of prayer from our holy faith, contained in Holy Scripture and the Church's teaching, as well as from her immemorial prayer practices, evident in her public worship and the spiritual lives of those elect souls who knew how to pray best. It is in the biographies of saints and their writings that we find the best commentaries – as they are bursting with life and love –on the immemorial teaching of the Church about spiritual communion with the Lord of hosts, which is prayer.