Arnold Dallimore is the author of a two-volume biography of 18th century evangelist George Whitefield. He explains one of the reasons he wrote the book.
Nevertheless, the book goes forth with a mission. It is written with the profound conviction that the paramount need of the twentieth century is a mighty evangelical revival such as that which was experienced two hundred years ago. Thus, I have sought to show what were the doctrines used of God in the eighteenth-century Revival, and to display the extraordinary fervor which characterized the men whom God raised up in the blessed work. Yea, this book is written in the desire – perhaps in a measure of inner certainty – that we shall see the great Head of the Church once more bring into being His special instruments of revival, that He will again raise up unto Himself certain young men whom He may use in this glorious employ. And what manner of men will they be? Men mighty in the Scriptures, their lives dominated by the sense of greatness, the majesty and holiness of God, and their minds and hearts aglow with the great truths of the doctrines of grace. They will be men who have learned what it is to die to self, to human aims and personal ambitions; men who are willing to be ‘fools for Christ’s sake’, who will bear reproach and falsehood, who will labor and suffer, and whose supreme desire will be, not to gain earth’s accolades, but to win the Master’s approbation when they appear before His awesome judgment seat. They will be men who will preach broken hearts and tear-filled eyes, and upon whose ministries God will grant an extraordinary effusion of the Holy Spirit, and who will witness ‘signs and wonders following’ in the transformation of multitudes of human lives.
Indeed, this book goes forth with the earnest prayer that, amidst the rampant iniquity and glaring apostasy of the twentieth century God will use it toward the raising up of such men and toward the granting of a mighty revival such as was witnessed two hundred years ago.
All I can add is that everything Dallimore said about the twentieth century applies to the twenty-first, too.