In the Day of Thy Power: The Scriptural Principles of Revival Paperback by Arthur Wallis and published by CLC.
"Oh, that You would rend the heavens! That You would come down!" Millions have prayed that, and pray it now. In the Day of Thy Power is filled with plentiful quotations from eyewitnesses of revival and with inescapable biblical authority for such "times of refreshing... from the presence of the Lord." It unfolds the conditions by which God still comes, as in apostolic days, with "mighty signs and wonders, by the power of the Spirit of God." This first book of Arthur Wallis, written in 1956, was an immediate success when first published and has become a classic on the subject of revival.