Besides, he was destined to be the great theologian of Christianity and the principal writer of the New Testament. Now the New grew out of the Old; the one is in all its parts the prophecy and the other the fulfillment. But it required a mind saturated not only with Christianity, but with the Old Testament, to bring this out; and, at the age when the memory is most retentive, Paul acquired such a knowledge of the Old Testament that everything it contains was at his command: its phraseology became the language of his thinking; he literally writes in quotations, and he quotes from all parts with equal facility--from the Law, the Prophets, and the Psalms. Thus was the warrior equipped with the armor and the weapons of the Spirit before he knew in what cause he was to use them. 27. His Religious Life.--Meantime what was his moral and religious state? He was learning to be a religious teacher; was he himself religious? Not all who are sent to college by their parents to prepare for the sacred office are so, and in every city of the world the path of youth is beset with temptations which may ruin life at its very beginning. Some of the greatest teachers of the Church, such as St. Augustine, have had to look back on half their life blotted and scarred with vice or crime. No such fall defaced Paul's early years. Whatever struggles with passion may have raged in his own breast, his conduct was always pure. Jerusalem was no very favorable place, in that age, for virtue. It was the Jerusalem against whose external sanctity, but internal depravity, our Lord a few years afterward hurled such withering invectives; it was the very seat of hypocrisy, where an able youth might easily have learned how to win the rewards of religion, while escaping its burdens. But Paul was preserved amidst these perils, and could afterward claim that he had lived in Jerusalem from the first in all good conscience. 28. He had brought with him from home the conviction, which forms the basis of a religious life, that the one prize which makes life worth living is the love and favor of God. This conviction grew into a passionate longing as he advanced in years, and he asked his teachers how the prize was to be won. Their answer was ready--By the keeping of the law. It was a terrible answer; for the Law meant not only what we understand by the term, but also the ceremonial law of Moses and the thousand and one rules added to it by the Jewish teachers, the observance of which made life a purgatory to a tender conscience.