It was one of the great experimental problems much agitated among the greater evangelical divines of that deep, clear-eyed, and honest day, Why the truly regenerate are all left so full of all manner of indwelling sin. We never hear that question raised nowadays, nor any question at all like that. The only difficulty in our day is why any man should have any difficulty about his own indwelling sin at all. But neither Beattie, nor Rutherford, nor any of the masters who remain to us had got so far as we. And as for the Antinomian, perfectionist, and higher-life preachers of that day, they are all so dead and forgotten that you would not know their names even if I repeated them. Beattie, as a beginner in the spiritual life, had made this still not uncommon mistake. He had taken those New Testament passages in which the apostles portray an ideal Christian man as he stands in the election and calling of God, and as he will be found at last and for ever in heaven, and he had prematurely and inconsequently applied all that to himself as a young man under sanctification and under the painful and humiliating beginnings of it; and no wonder that, so confusing the very first principles of the Gospel, he confused and terrified himself out of all peace and all comfort and all hope. Now, that was just the kind of difficulty with which Rutherford could deal with all his evangelical freedom and fulness, depth and insight. No preacher or writer of that day held up the absolute necessity of holiness better than Rutherford did; but then, that only the more compelled him to hold up also such comfort as he conveys in his consoling and reassuring letter to despairing Beattie: 'Comparing the state of one truly regenerate, whose heart is a temple of the Holy Ghost, with your own, which is full of uncleanness and corruption, you stand dumb and dare not call Christ heartsomely your own. But, I answer, the best regenerate have their defilements, and, wash as they will, there will be the filth of sin in their hearts to the end. Glory alone will make our hearts pure and perfect, never till then will they be absolutely sinless.' And if we, Rutherford's so weak-kneed successors, preached the law of God and true holiness as he preached those noble doctrines, the sheer agony of our despairing people would compel us to preach also the true nature, the narrow limits, and the whole profound laws of evangelical sanctification as we never preach, and scarce dare to preach, those things now. They who preach true holiness best are just thereby the more compelled to preach its partial, tentative, elementary, and superficial character in this life. And the hearer who knows in the word of God and in his own heart what indeed true holiness is, will insist on having its complementary truths frequently preached to him to keep him from despair; or else he will turn continually to those great divines who, though dead, yet preach such things in their noble books. And that those books are not still read and preached among us, and that the need for them and their doctrines is so little felt, is only another illustration of the true proverb that where no oxen are the crib is clean.
James Beattie was in very good company when he said that he must have more assurance, both of his gifts and his graces, before he could enter on his ministry. For Moses, and Isaiah, and Jeremiah, and many another minister who could be named, have all felt and said the same thing. Now that he is near the door of the pulpit, Beattie feels that he cannot enter it till he has more certainty that it is all right with himself. But our young ministers will attain to assurance not so much by consulting Rutherford, skilled casuist in such matters as he is, as by themselves going forward in a holy life and a holy ministry. 'It is not God's design,' says Jonathan Edwards, 'that men should obtain assurance in any other way than by mortifying corruption, increasing in grace, and obtaining the lively exercises of it. Assurance is not to be obtained so much by self-examination as by action. Paul obtained assurance of winning the prize more by running than by reflecting. The swiftness of his pace did more toward his assurance of the goal than the strictness of his self-examination.' 'I wish you a share of my feast,' replies Rutherford. 'But, for you, hang on our Lord, and He will fill you with a sense of His love, as He has so often filled me. Your feast is not far off. Hunger on; for there is food already in your hunger for Christ. Never go away from Him, but continue to fash Him; and if He delays, yet come not away, albeit you should fall aswoon at His feet.' Pray, says Rutherford, and you will not long lack assurance. Work, says Edwards, and assurance of God's love will be an immediate earnest of your full wages.