That is is natural for a believer to grow - a truth which is to be impressed upon your heart - is evident for the following reasons:
First, God promises that He will cause His regenerated to grow. "Those that be planted in the house of the LORD shall flourish in the courts of our God" (Psa. 92:13); "I will be as the dew unto Israel: he shall grow as the lily, and cast forth his roots as Lebanon. His branches shall spread, and his beauty shall be as the olive tree, and his smell as Lebanon" (Hosea 14:5-6); "Ye shall go forth, and grow up as calves of the stall" (Mal. 4:2). God's promises are in truth, and He whohas declared them will also perform them. Let the godly person remind the Lord of this.
Secondly, it is the very nature of spiritual life to grow. Wherever the principle of this life is to be found, it can be no different for it must grow. "But the path of the just is as the shining light, that shineth more and more unto the perfect day" (Prov. 4:18); "The righteous also shall hold on his way, and he that hath clean hands shall be stronger and stronger" (Job 17:9). This refers to the children of God, who are compared to palm and cedar trees (Psa. 92:12). As natural as it is for children and trees to grow, so natural is growth for the regenerated children of God.
Thirdly, the growth of His children is the goal and objective God has in view by administering the means of grace to them. "And He gave some, apostles; and some, prophets; and some, evangelists; and some, pastors and teachers; for the perfecting of the saints...that we henceforth be no more children...but speaking the truth in love, may grow up into Him in all things, which is the Head" (Eph. 4:11-15). This is also to be observed in 1 Peter 2:2: "as newborn babes, desire the sincere milk of the word, that ye may grow thereby." God will reach His goal and His word will not return to Him void; thus God's children will grow in grace.
Fourthly, it is a duty to which God's children are continually exhorted, and their activity is to consist in a striving for growth. That it is their duty is to be observed in the following passages: "But grow in grace, and in the knowledge of our Lord and Saviour Jesus Christ" (2 Peter 3:18); "He that is righteous, let him be righteous still: and he that is holy, let him be holy still" (Rev. 22:11). The nature of this activity is expressed as follows: "Not as though I had already attained, either were already perfect: but I follow after" (Phil. 3:12). If it were not necessary for believers to grow the exhortations to that end would be in vain.
Fifthly, this is also conveyed by the difference in believers in regard to their condition and the measure of grace. In the church there are children, young men, and fathers. "I write unto you, fathers, because ye have known Him that is from the beginning. I write unto you, young men, because ye have overcome the wicked one. I write unto you, little children, because ye have known the Father" (1 John 2:13). It is in graceas it is in nature: first a child, then a young man, and after that a father. All this proves it to be a certainty that it is neither the mere duty nor that it would be merely a good thing for the godly to grow, but it is their nature. Thus, those who do not manifest any growth are not believers. Hereby, the unconverted ought immediately to be convinced that as yet it is not well with them. Furthermore, this can, first of all, be of comfort to God's children regarding the grace they possess, and they can already in the beginning be stirred up to strive for spiritual growth.
- Wilhelmus a Brakel, The Christian's Reasonable Service, Vol. IV, 139-141.