St. Paul often expresses the intense intellectual satisfaction which Christianity brought him, and the joy he experienced in applying it to the solution of the problems of life. The light which Christianity cast on the universe was to him, he says, like the morning of creation, when God said, Let there be light, and there was light. Before, all was darkness and chaos, but then all became sunshine and order. He often speaks with wondering gratitude of the fact that the mystery which had been hidden from ages and from generations had been revealed to him: Eye had not seen, nor ear heard, neither had entered into the heart of man, the things which God had prepared for them that love Him, but God had revealed them unto him by His Spirit. And by this mystery he meant the tangle of God's providence in history, which the coming of Christ disentangled and smoothed out into a web whose pattern the mind could discern.
Having himself received Christianity as an intellectual system, he very specially addressed himself to the intellect of others. The door of the kingdom of heaven, it has been beautifully said, can only be opened from the inside; but to that observation this other may be added, that in a sense there are many doors, but each man can only open to others the one by which he has entered himself. Christianity had come to St. Paul as the truth about God and the world and himself. There was plenty of emotion besides; but the emotion for him came after the clear intellectual conviction and sprang out of it. And he expected that others would receive Christianity in the same way. Therefore he never spared the minds of those he addressed; he expected them to think; and he would have said that, if they would not open and exert their minds, they could not receive Christianity.
I hardly know anything more puzzling than the audacity with which he cast himself on the minds of his hearers and trusted them to understand him, when he was thinking his strongest and his deepest. Imagine an epistle of his arriving in Rome or Ephesus, and read out in the audience of the church for the first time. Who were the hearers? The majority of them were slaves; many had till a short time before been unconcerned about religion; in all probability not a tithe of them could read or write. Yet what did Paul give them? Not milk for babes; not a compost of stories and practical remarks; but the Epistle to the Romans, with its strict logic and grand ideas, or the Epistle to the Ephesians, with its involved sentences and profound mysticism. He must have believed that they would understand what he wrote, though scholarship has considered it necessary to pile up a mountain of commentaries on these epistles. Christianity, as it went through the cities of the world in St. Paul's person, must have gone as a great intellectual awakening, which taught men to use their minds in investigating the profoundest problems of life.
How deeply he was interested in the intellectual reception of the Gospel is shown by the earnestness with which he prays that his converts may excel in mental grasp of the truth. "I pray," he says, "that your love may abound yet more and more in knowledge and in all judgment." And again he says, "Making mention of you in my prayers, that the God of our Lord Jesus Christ, the Father of glory, may give unto you the spirit of wisdom and revelation in the knowledge of Him, the eyes of your understanding being enlightened," etc.
But nothing proves so clearly the value which he set on this element of Christianity as his earnestness that his version of the Gospel should be kept pure and entire. He called upon younger ministers, like Timothy and Titus, to guard it as a precious treasure and to transmit it to faithful men who would be able to teach others also. It filled him with the most poignant anxiety and pain when the minds of his converts were assailed with doctrines subversive of the truth which he had taught. He had to encounter assaults of this kind coming from the side of orthodoxy as well as of heterodoxy, and no small portion of his energy had to be expended in refuting them. You remember, for example, with what a heat of zeal and affection he cast himself on the Galatians, when they had lent an ear to false teachers: "O foolish Galatians, who hath bewitched you?" "If any man preach any other gospel unto you than that which ye have received, let him be accursed."