The textual evidence is in favor of the reading that has two imperatives rather than two infinitives. The sense, too, is against the latter, for this negative and this positive are not additions to the infinitive "to present," they elucidate what this spirit service really requires. The two imperatives are opposites not only in regard to their prepositional prefixes but also in the root words themselves. This difference is lost when we translate: "be not conformed but be transformed," for the English root word "form" is the same. [Greek] "Schema" outward conformation, fashion; but [Greek] morpha is, the essential form which fully expresses the essence or real, being. We have the latter in "metamorphosis." We can do no better in English than to follow Field (M.-M. 613): "be not outwardly conformed but be inwardly transformed."
The Greek "eon" = a great stretch of time but one that is marked and characterized and thus made a unit by what transpires in it, "world" in this sense, namely when "this eon" is referred to, dieser Zeitlaufj. This eon is "wicked," Gal. 1:4; its god is the devil, II Cor. 4:4; it is the eon of this cosmos. It is contrasted with "the eon about to come" which the Parousia ushers in, the -eon of eternal blessedness, of the new earth.
Not even outwardly are we to adopt the fashion of the eon in which we now live, the ways the of the world. The present imperative asks us to shun this conformity during the entire course of our lives. Even in outward fashion the Christian is to be different, separate from the world. Our visible conversation and life as men see us are to show that their ways are not our ways; our conversation (citizenship) is in heaven, Phil. 3:20. We are only pilgrims here and not citizens. Since we expect to go to heaven, our conduct here reflects that fact and is unlike that of men who seek their all in this eon. There is danger that the Christian may adopt at least some of the world's ways, run with worldly men (I Pet. 4:4), especially when they mock us if we do not. Christians sometimes imagine that they can do this without injury to themselves, can remain unspotted from the world amid worldly, unchristian associations, amid worldly and questionable pleasures. To howl a bit with the wolves, to do as the Romans do because we are in Rome, to avoid the abuse of the world and not to lose all this tainted pleasure and ad vantage while still holding fast to Christ, does not seem so wrong. The resultant casualties are many and exceedingly sad.
As is the case in so many instances in Holy Writ, the opposite is far more than an opposite: not even outward conformity - no less than constant inward transformation. This is what presenting our bodies as a living sacrifice and thus as our reasonable cultus means. What we do with our bodies and our whole bodily life is to be the evidence of a constant inner metamorphosis, one that is accomplished "by the renewing of the mind so that you test out what the will of God is," test out "the thing (really) good and well-pleasing and complete," making our mind conform to this divine newness and rejecting everything else as being spurious. Here there is the same concentrated richness of thought as in v. 1. The inner transformation begins at the moment of our justification and is to advance throughout life until God completes it in death.
The dative of means states that this transformation is effected "by the renewing of the mind." In 6 :4 we have "newness of life," the condition; here we have "the renewing," the process. The [Greek] chainos occurring in both terms is "new" as the opposite of "old" in our old man. And [Greek] noms is "mind" as "the organ of moral thinking and knowing" (C. K. 764) and thus matches [Greek] logukos used in v. 1. The Christian's inward transformation is effected when his moral mentality becomes renewed, the very mentality itself, so that it no longer thinks, understands, and judges as it once did but so that it cannot do so because it is in a process of renewal that advances steadily. The Christian minds the things of the spirit, a thing he never did before, and ceases minding the things of the flesh, a thing he always did before (8:5, 6); as a son of God he is led by the Spirit of God in his very mind (8:14). His use of the body shows it.
[Greek] Eis to with the infinitive, as so often (3:26; 4:11, twice; 4:18), states the result, namely what the mind does in consequence: "so that you keep testing out (durative) what the will of God is," as men test out coins or metal by accepting the genuine and rejecting and throwing out the spurious. The renewed mind is even bent and following God's will, what God wants of us; it has utterly ceased its old disregard of God's will, its old folly of contenting itself with its own will.
We do not regard the three following words as adjectives: "the good and acceptable and perfect will of God" (our versions). The second is "well-pleasing" and, as in v. 1, means "well-pleasing to God" and hence cannot modify "the will of God." The third means "complete," and the implication of an "incomplete" will of God is distressing. These adjectives are substantivized, are treated as a unit (one article), and form an apposition: test out the will of God, (namely test out) "the thing (really) good," etc. For God ever wills [Greek] to agathon, "the thing morally good and beneficial," and never anything that is not good. And this thing is the one "well-pleasing" to him; he says so in his Word which we use as our criterion in making our test. And thus also this good and well-pleasing thing is "complete," easily distinguished from, the reductions to which even Christians at times subject the will of God by claiming he does not will this or that. Worldly tendencies in the church excuse themselves in this way.
This threefold designation is an apposition: "what is the will, namely what is this thing that is at once good; pleasing to God, and complete." The renewed mind of the Christian ever seeks to prove this in life. We cannot, then, make "the good thing," etc., the criterion, the touchstone for our testing out what God's will is. We never say that only what is in our judgment good is God's will; -or what we think is well pleasing to him; or what we consider morally and spiritually complete. No; testing out what God wants is discovering the thing that is good for us, pleasing to him, complete in itself. And what God's will is, namely this thing which he wills, we discover from his Word and from that alone, and we subject all our own conceptions of what is good, etc., wholly to that Word. Every test made without the Word is deceptive and wrong.
Does v. 1 apply particularly to the Jewish Christians because it speaks of "living sacrifice"? No more than do 6:11, 13: "alive to God," "as alive from the dead." Does v. 2 apply particularly to Gentile Christians? No more than any other verse in this chapter. Just because they are now Christians, Jewish Christians are in just as great danger as are Gentile Christians of being conformed to worldly ways in a great city like Rome which offered so many temptations. It is well known that throughout the Gentile world Jews became loose and lax in their Judaism and fell into many evil, pagan ways. When Paul specifies in v. 3: "I say to everyone that is among you," the reason is not that, when he used "brethren" in v. 1, he had in mind two groups, v. 1 indicating the one, v. 2 the other; the reason lies in what Paul says in v. 3-8. Verses 1 and 2 befit the whole, in v. 3-8 individualization is necessary.
from Interpretations of Romans, by R. C. H. Lenski, Copyright 1945, Wartburg Press, Columbus, OhioApril 24,2003.