It is under a deep impression that the place and power of prayer in the Christian life is too little understood, that this book has been written. I feel sure that as long as we look on prayer chiefly as the means of maintaining our own Christian life, we shall not know fully what it is meant to be. But when we learn to regard it as the highest part of the work entrusted to us, the root and strength of all other work, we shall see that there is nothing that we so need to study and practise as the art of praying aright.