The book was written before the great oecumenical movement for unity arose after the war. It could not certainly in this form have been written unless the author, born a Roman Catholic, had fought his way up to an oecumenical position through his studies and experience of life. Prayer is the great bond of union of Christendom; and not only of Christendom, but of all mankind. Prayer is the most tangible proof of the fact that the whole of mankind is seeking after God; or to put it mare correctly that it is sought by God.