Trinity (see above), of original sin, and of atonement. Such an advance from faith to knowledge, such a development of revealed truths into proved truths of reason, is absolutely necessary. We cannot dispense with the truths of revelation, but we must not remain content with simply believing them, but must endeavor to comprehend them; for they have been revealed in order that they may become rational. They are, as it were, the sum which the teacher of arithmetic tells his pupils beforehand so that they may guide themselves by it; but if they content themselves with this solution--which was given merely as a guide--they would never learn to calculate. Hand in hand with the advance of the understanding goes the progress of the will. Future recompenses, which the New Testament promises as rewards of virtue, are means of education, and will gradually fall into disuse: in the highest stage, the stage of purity of heart, virtue will be loved and practiced for its own sake, and no longer for the sake of heavenly rewards. Slowly but surely, along devious paths which are yet salutary, we are being led toward that great goal. It will surely come, the time of consummation, when man will do the good because it is good, this time of the new, eternal Gospel, this third age, this "Christianity of reason." Continue, Eternal Providence, thine imperceptible march; let me not despair of thee because it is imperceptible, not even when to me thy steps seem to lead backward. It is not true that the straight line is always the shortest. [Footnote 1: _Die Erziehung des Menschengeschlects_.] With the thought that every individual must traverse the same course as that by which the race attains its perfection, Lessing connects the idea of the transmigration of souls. Why may not the individual man have been present in this world more than once? Is this hypothesis so ridiculous because it is the oldest? If Lessing abandoned the ranks of the deists by his recognition of the fact that the positive religions contain truth in a gradual process of purification, by his free criticism, on the other hand, he broke with the orthodox, whose idolatrous reverence for the Bible was to him an abomination. The letter is not the spirit, the Bible is not religion, nor yet its foundation, but only its records. Contingent historical truths can never serve as a proof of the necessary truths of reason. Christianity is older than the New Testament.