The terms “renew,” “renewing,” are not of frequent occurrence in our English Bible. In the New Testament they do not occur at all in the Gospels, but only in the Epistles (Paul and Hebrews), where they stand, respectively, for the Greek terms ἀνακαινόω (2 Cor. 4:16, Col. 3:10) with its cognates, ἀνακαινίζω (Heb. 6:6) and ἀνανεόομαι (Eph. 4:23), and ἀνακαίνωσις (Rom. 12:2, Tit. 3:5). If we leave to one side 2 Cor. 4:16 and Heb. 6:6, which are of somewhat doubtful interpretation, it becomes at once evident that a definite theological conception is embodied in these terms. This conception is that salvation in Christ involves a radical and complete transformation wrought in the soul (Rom. 12:2, Eph. 4:23) by God the Holy Spirit (Tit. 3:5, Eph. 4:24), by virtue of which we become “new men” (Eph. 4:24, Col. 3:10), no longer conformed to this world (Rom. 12:2, Eph. 4:22, Col. 3:9), but in knowledge and holiness of the truth created after the image of God (Eph. 4:24, Col. 3:10, Rom. 12:2). The conception, it will be seen, is a wide one, inclusive of all that is comprehended in what we now technically speak of as regeneration, renovation and sanctification. It embraces, in fact, the entire subjective side of salvation, which it represents as a work of God, issuing in a wholly new creation (2 Cor. 5:17, Gal. 6:15, Eph. 2:10). What is indicated is, therefore, the need of such a subjective salvation by sinful man, and the provision for this need made in Christ (Eph. 4:20, Col. 3:11, Tit. 3:6).
The absence of the terms in question from the Gospels does not in the least argue the absence from the teaching of the Gospels of the thing expressed by them. This thing is so of the essence of the religion of revelation that it could not be absent from any stage of its proclamation. That it should be absent would require that sin should be conceived to have wrought no subjective injury to man, so that he would need for his recovery from sin only an objective cancelling of his guilt and reinstatement in the favor of God. This is certainly not the conception of the Scriptures in any of their parts. It is uniformly taught in Scripture that by his sin man has not merely incurred the divine condemnation but also corrupted his own heart; that sin, in other words, is not merely guilt but depravity: and that there is needed for man’s recovery from sin, therefore, not merely atonement but renewal; that salvation, that is to say, consists not merely in pardon but in purification. Great as is the stress laid in the Scriptures on the forgiveness of sins as the root of salvation, no less stress is laid throughout the Scriptures on the cleansing of the heart as the fruit of salvation. Nowhere is the sinner permitted to rest satisfied with pardon as the end of salvation; everywhere he is made poignantly to feel that salvation is realized only in a clean heart and a right spirit.
In the Old Testament, for example, sin is not set forth in its origin as a purely objective act with no subjective effects, or in its manifestation as a series of purely objective acts out of all relation to the subjective condition. On the contrary, the sin of our first parents is represented as no less corrupting than inculpating; shame is as immediate a fruit of it as fear (Gen. 3:7). And, on the principle that no clean thing can come out of what is unclean (Job 14:4), all that are born of woman are declared “abominable and corrupt,” to whose nature iniquity alone is attractive (Job 15:14–16). Accordingly, to become sinful, men do not wait until the age of accountable action arrives. Rather, they are apostate from the womb, and as soon as they are born go astray, speaking lies (Ps. 58:3): they are even shapen in iniquity and conceived in sin (Ps. 51:5). The propensity ( )ֵיֶערof their heart is evil from their youth (Gen. 8:21), and it is out of the heart that all the issues of life proceed (Prov. 4:23, 20:11). Acts of sin are therefore but the expression of the natural heart, which is deceitful above all things and desperately sick (Jer. 17:9). The only hope of an amendment of the life, lies accordingly in a change of heart; and this change of heart is the desire of God for His people (Deut. 5:29) and the passionate longing of the saints for themselves (Ps. 51:10). It is, indeed, wholly beyond man’s own power to achieve it. As well might the Ethiopian hope to change his skin and the leopard his spots as he who is wonted to evil to correct his ways (Jer. 13:23); and when it is a matter of cleansing not of hands but of heart—who can declare that he has made his heart clean and is pure from sin (Prov. 20:9)? Men may be exhorted to circumcise their hearts (Deut. 10:16, Jer. 4:4), and to make themselves new hearts and new spirits (Ezek. 18:31); but the background of such appeals is rather the promise of God than the ability of man (Deut. 5:29, Ezek. 11:19, cf. Keil in loc.). It is God alone who can “turn” a man “a new heart” (1 Sam. 10:9), and the cry of the saint who has come to understand what his sin means, and therefore what cleansing from it involves, is ever, “Create ( )ָּב ָר אin me a new heart, O God, and renew ( )ָח ַד ׁשa steadfast spirit within me” (Ps. 51:10 [12]). The express warrant for so great a prayer is afforded by the promise of God who, knowing the incapacity of the flesh, has Himself engaged to perfect His people. He will circumcise their hearts, that they may love the Lord their God with all their heart and with all their soul; and so may live (Deut. 30:6). He will give them a heart to know Him that He is the Lord; that so they may really be His people and He their God (Jer. 24:7). He will put His law in their inward parts and write it in their heart so that all shall know Him (Jer. 31:33, cf. 32:39). He will take the stony heart out of their flesh and give them a heart of flesh, that they may walk in His statutes and keep his ordinances and do them, and so be His people and He their God (Ezek. 11:19). He will give them a new heart and take away the stony heart out of their flesh; and put His Spirit within them and cause them to walk in His statutes and keep His judgments and do them: that so they may be His people and He their God (Ezek. 36:26, cf. 37:14). Thus the expectation of a new heart was made a substantial part of the Messianic promise, in which was embodied the whole hope of Israel.