Romans 12:2

“And be not conformed to this world, etc..] By this world is meant, either the Mosaic dispensation, and Jewish church state, so called in opposition to abh µlw[, “the world to come”, the Gospel dispensation; in which there were a worldly sanctuary, and the rites and ceremonies of which are styled the rudiments and elements of the world; to which believers in the present state are by no means to conform, there being sacrifices and ordinances of another nature, it is the will of God they should observe and attend unto: or else the men of the world are designed, carnal and unregenerate men, among whom they formerly had their conversation, from among whom they were chosen, called, and separated,…”

“And be ye not conformed to this world--Compare Eph 2:2; Gal 1:4, Greek. but be ye transformed--or, "transfigured" (as in Mat 17:2; and Co2 3:18, Greek). by the renewing of your mind--not by a mere outward disconformity to the ungodly world, many of whose actions in themselves may be virtuous and praiseworthy; but by such an inward spiritual transformation as makes the whole life new--new in its motives and ends, even where the actions differ in nothing from those of the world--new, considered as a whole, and in such a sense as to be wholly unattainable save through the constraining power of the love of Christ. that ye may prove--that is, experimentally. (On the word "experience" see on Rom…”

“And be not conformed ... - The word rendered “conformed” properly means to put on the form, fashion, or appearance of another. It may refer to anything pertaining to the habit, manner, dress, style of living, etc., of others. Of this world - τῷ αἰῶνι τούτῳ tō aiōni toutō. The word which is commonly rendered “world,” when applied to the material universe, is κόσμος kosmos, “cosmos.” The word used here properly denotes an age, or generation of people. It may denote a particular generation, or it may be applied to the race. It is sometimes used in each of these senses. Thus, here it may mean that Christians should not conform to the maxims, habits, feelings, etc., of a wicked,…”

“And be not conformed - Neither in judgment, spirit, nor behaviour. To this world - Which, neglecting the will of God, entirely follows its own. That ye may prove - Know by sure trial; which is easily done by him who has thus presented himself to God. What is that good, and acceptable, and perfect will of God - The will of God is here to be understood of all the preceptive part of Christianity, which is in itself so excellently good, so acceptable to God, and so perfective of our natures. Romans 12:3”

“12:2 this world (literally this age): The division of history into two ages was typical of the Jewish worldview. Early Christians adapted this point of view, identifying the coming of Christ as the time when the new age of salvation began. Unexpectedly, however, the new age did not bring an end to the old age. The old way of thinking and living continues, and it is a source of temptation even to Christians who seek to conform their lives to the values of the new age.”

“be not: Exo 23:2; Lev 18:29, Lev 18:30; Deu 18:9-14; Joh 7:7, Joh 14:30, Joh 15:19, Joh 17:14; Co1 3:19; Co2 4:4, Co2 6:14-17; Gal 1:4; Eph 2:2, Eph 4:17-20; Jam 1:27, Jam 4:4; Pe1 1:14, Pe1 1:18, Pe1 4:2; Pe2 1:4, Pe2 2:20; Jo1 2:15-17, Jo1 3:13, Jo1 4:4, Jo1 4:5, Jo1 5:19; Rev 12:9, Rev 13:8 be ye: Rom 13:14; Psa 51:10; Eze 18:31, Eze 36:26; Co2 5:17; Eph 1:18, Eph 4:22-24; Col 1:21, Col 1:22, Col 3:10; Tit 3:5 prove: Rom 12:1; Psa 34:8; Eph 5:10, Eph 5:17; Pe1 2:3 good: Rom 12:1, Rom 7:12, Rom 7:14, Rom 7:22; Psa 19:7-11, Psa 119:47, Psa 119:48, Psa 119:72, Psa 119:97, Psa 119:103, Psa 119:128, Psa 119:174; Pro 3:1-4; Pro 3:13-18; Gal 5:22-23; Eph 5:9; Col 4:12; Th1 4:3; Ti2 3:16, Ti2…”