Evangelical holiness, it will be recollected, is nothing more nor less than perfect love. Love is based, in part, upon knowledge, and is necessarily based upon it. It is entirely evident, that we can never love an object of which we have no knowledge; and it is equally so, that, in proportion as our knowledge extends, we have a wider intellectual basis for the action of this principle. And accordingly every new manifestation of God's character, every new exhibition of his attributes, every additional development of his providences, will furnish new occasions for accessions of love. It is the privilege, therefore, of a person perfected in love, and consequently a holy person, to increase in holiness in exact proportion with his increase in knowledge.
Again, it is well known that there is a great law of our mental nature, termed the law of HABIT. The law is, that increased facility and strength of mental action results from repetition or practice. There does not appear to be a power of the mind, either intellectual or sensitive, which may not feel the influence of this law. And according to this law, every exercise of love, when the exercises are continuously successive, will give place to another, which is increased in strength. And hence a holy being, (not one who is holy to day and sinning tomorrow, and so on alternately,) but a holy being, who continues to be so, will necessarily go on from one degree of strength to another. And we may add, by way of illustration, that it seems to be the same here, as it is in regard to depravity. Our theologians assure us, that man is by nature entirely depraved. But they also agree in asserting, that entireness of depravity does not preclude the idea of growth in depravity. They admit that the law of habit strengthens the intensity of the depraved element. A depraved man is more depraved than a depraved child; and a depraved devil is more depraved than a depraved man. If theologians generally propound as sound doctrine the idea of growth in the matter of depravity, when the depravity is entire, it would be difficult to show its unsoundness in the matter of holiness.
And there is another important consideration. There are grounds for the remark, that we may indirectly increase the strength of holy emotions and desires, by a removal of the various obstacles which oppose and obstruct their exercise. The speed of a vessel or of a railroad car depends not only upon the amount of the propelling power, whatever that power may be, but also, in part, upon the number and greatness of the obstacles to be overcome. If the obstacles are many and great, the speed will be less. Now the sanctified person is continually acquiring knowledge, not only in relation to the great and adorable object of his perfected love, but also in relation to his own physical and intellectual infirmities, the nature of temptations, and the subtle arts of the adversary of souls. In these infirmities, temptations, and evil arts, he finds very serious obstacles to his progress in holiness. But every day's experience, under the instructions and guidance of the Holy Spirit, teaches their nature and diminishes their power. He learns where his weakness is, and understands better than he did at first how to counteract it. He knows the artifices of the adversary, the insidious manner of his approaches, and the way in which he can be resisted and defeated. And the result of this knowledge is, that many serious obstacles, which existed before and which perplexed his progress, are removed. His increased knowledge of the character of God, the influence of the law of habit, the imparted influences of the Holy Spirit, have their natural and unobstructed effect, and accelerate, as they would not do under other circumstances, the ascendant flight of the soul.
These considerations evidently show, that the idea of growth in holiness, when the heart is already sanctified to God, is not an unreasonable one. On the contrary, it would seem on any principles of reason applicable to the case, that the growth of a sanctified soul in holiness would be much more rapid than that of a soul but partially sanctified. The testimony of those, who have arrived at the state of assurance of faith and perfected love, confirms these views. Their testimony is, that, after having reached this state, their growth in grace is much more rapid and sure than it was before. They are conscious of increased power against temptation, and of an increase of union with the divine will, to an extent unknown in their previous experience. What growth, then, must there be in angel minds, which are neither obstructed by inward nor by outward evils in their progress! What expansion with each revolving day! What increased intensity of desire! What higher and more triumphant energies of love!
In conclusion, we exhort those, who are sanctified to the Lord, to grow abundantly in holiness. Of two persons, both of whom are truly, holy persons, one may grow in holiness more rapidly and surely than another. This is an important fact, and one that is often overlooked. The difference of growth in holiness, after the experience of sanctification, seems to us to depend, next to believing and earnest application for divine assistance, upon growth in KNOWLEDGE. Little claim has any one to the character of a holy person, who is willing to be ignorant. We have not reference in this remark to the mere knowledge of natural things, which oftentimes perplexes rather than promotes the inward life, but to religious knowledge; to any thing and every thing which throws light upon the character, providences, and the will of God; and to whatever illustrates the character, relations, and moral and religious duties of man. Holiness, considered in its full extent, is a great study; and he only, who is willing to be a diligent and faith-full student, will understand it. Hence we are told in the second epistle of Peter, that God hath given us all things that pertain unto life and godliness, " through the KNOWLEDGE of him that has called us to glory and virtue; " and are directed. in the same chapter to add "to our faith virtue, and to virtue KNOWLEDGE.
— edited from The Interior or Hidden Life (1844) Part 2, Chapter 15.