His work is in the form of a letter to a young Oxford friend, who was assumed to be yearning for a rational faith, 'as it was his duty to prove all things.' 'Rational faith!' says Dodwell in effect, 'the thing is impossible; it is a contradiction in terms. If you must prove all things, you will hold nothing. Faith is commanded men as a duty. This necessarily cuts it off from all connection with reason. There is no clause providing that we should believe if we have time and ability to examine, but the command is peremptory. It is a duty for every moment of life, for every age. Children are to be led early to believe, but this, from the nature of the case, cannot be on rational grounds. Proof necessarily presupposes a suspension of conviction. The rational Christian must have begun as a Sceptic; he must long have doubted whether the Gospel was true or false. Can this be the faith that "overcometh the world"? Can this be the faith that makes a martyr? No! the true believer must open Heaven and see the Son of Man standing plainly before his eyes, not see through the thick dark glass of history and tradition. The Redeemer Himself gave no proofs; He taught as one having authority, as a Master who has a right to dictate, who brought the teaching which He imparted straight from Heaven. In this view of the ground of faith, unbelief is a rebellious opposition against the working of grace. The union of knowledge and faith is no longer nonsense. All difficulties are chased away by the simple consideration "that with men it is impossible, but with God all things are possible." Philosophy and religion are utterly at variance. The groundwork of philosophy is all doubt and suspicion; the groundwork of religion is all submission and faith. The enlightened scholar of the Cross, if he regards the one thing needful, rightly despises all lower studies. When he turns to these he leaves his own proper sphere. Julian was all in the wrong when he closed the philosophical schools to the Christians. He should have given them all possible privileges that they might undermine the principles of Christ. "Not many wise men after the flesh are called." All attempts to establish a rational faith, from the time of Origen to that of Tillotson, Dr. Clarke, and the Boyle lectures, are utterly useless. Tertullian was right when he said _Credo quia absurdum et quia impossibile est_, for there is an irreconcilable repugnancy in their natures between reason and belief; therefore, "My son, give thyself to the Lord with thy whole heart and lean not to thy own understanding."'