But, before he faces the rolling wave, the Apostle tells his readers why it is that, in reference to Christian doctrine, character is the necessary condition of intelligence. It is so for two reasons.
_First_, the word spoken by God in His Son has for its primary object, not speculation, but "righteousness."[95] Theology is essentially a practical, not a merely theoretical, science. Its purpose is to create righteous men; that is, to produce a certain character. When produced, this lofty character is sustained by the truths of the Gospel as by a spiritual "food," milk or strong meat. Christianity is the art of holy living, and the art is mastered only as every other art is learned: by practice or experience. But experience will suggest rules, and rules will lead to principles. The art itself creates a faculty to transform it into a science. Religion will produce a theology. The doctrine will be understood only by the possessor of that goodness to which it has itself given birth.
_Second_, the Apostle introduces the personal action of God into the question. Understanding of the higher truths is God's blessing on goodness,[96] and destruction of the faculty of spiritual discernment is His way of punishing moral depravity.[97] This is the general sense and purport of an extremely difficult passage. The threatened billow is still far away. But before it rolls over us, we seem to be already submerged under the waves. Our only hope lies in the Apostle's illustration of the earth that bears here thorns and there good grain.
Expositors go quite astray when they explain the simile as if it were intended to describe the effect on moral character of rightly or wrongly using our faculty of knowledge. The meaning is the reverse. The Apostle is showing the effect of character on our power to understand truth. Neither soil is barren. Both lands drink in the rain that often comes upon them. But the fatness of the one field brings forth thorns and thistles, and this can only mean that the man's vigour of soul is itself an occasion of moral evil. The richness of the other land produces plants fit for use by men, who are the sole reason for its tillage.[98] This, again, must mean that, in the case of some men, God blesses that natural strength which itself is neither good nor evil, and it becomes a source of goodness. We come now to the result in each case. The soil that brings forth useful herbs has its share of the Creator's first blessing. What the blessing consists in we are not here told, and it is not necessary to pursue this side of the illustration further. But the other soil, which gives its natural strength to the production of noxious weeds, falls under the Creator's primal curse and is nigh unto burning. The point of the parable evidently is that God blesses the one, that God destroys the other. In both cases the Apostle recognises the Divine action, carrying into effect a Divine threat and a Divine promise.
Let us see how the simile is applied. The terrible word "impossible" might indeed have been pronounced, with some qualification, over a man who had fallen under the power of evil habits. For God sets His seal to the verdict of our moral nature. To such a man the only escape is through the strait gate of repentance. But here we have much more than the ordinary evil habits of men, such as covetousness, hypocrisy, carnal imaginations, cruelty. The Apostle is thinking throughout of God's revelation in His Son. He refers to the righteous anger of God against those who persistently despise the Son. In the second chapter[99] he has asked how men who neglect the salvation spoken through the Lord can hope to shun God's anger. Here, he declares the same truth in a stronger form. How shall they escape His wrath who crucify afresh the Son and put Him to an open shame? Such men God will punish by hardening their hearts, so that they cannot even repent. The initial grace becomes impossible.