Romans 12:2

And be not conformed to this world
By this world is meant, either the Mosaic dispensation, and Jewish church state, so called in opposition to (abh Mlwe) , "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 who lie and live in wickedness, and therefore should not be conformed unto them: which is to be understood, not in a civil sense of conformity to them in garb and apparel, provided that pride and luxury are guarded against, and decency and sobriety observed, and the different abilities of persons and stations in life are attended to; or to any other civil usages and customs which are not contrary to natural and revealed religion; but of a conformity in a moral sense to the evil manners of men, to walk vainly, as other Gentiles do, to go into the same excess of riot with them; for this is contrary both to the principle and doctrine of grace, which teach men to deny ungodliness and worldly lusts: and of a compliance with the men of the world in a religious sense, by joining with them in acts of idolatry, superstition, and will worship, and in anything that is contrary to the order, ordinances, and truths of the Gospel.

But be ye transformed by the renewing of your mind;
which regards not the first work of conversion and renovation; for in this sense these persons were transformed, metamorphosed, changed, and renewed already; but the after progress and carrying on the work of renovation, the renewing of them day by day in the spirit of their minds; see ( Ephesians 4:23 ) ( 2 Corinthians 4:16 ) ; which believers should be desirous of, and pray for, and make use of those means which the Spirit of God owns for this purpose, attending to the spiritual exercises of religion, as reading, meditation, prayer, conference, the ministration of the word and ordinances, which is the reverse of conformity to the world: and the end to be attained hereby is,

that ye may prove what is that good, and acceptable, and perfect
will of God;
by which is meant not the secret will of God, which cannot be searched into, proved, and known, till time and facts discover it: but the revealed will of God, both in the law, as in the hands of Christ, which contains nothing but what is good; and which when done in faith, from a principle of love, and to the glory of God, is acceptable through Christ; and is perfect as a law of liberty, and rule of walk and conversation; and which is to be proved and approved of by all the saints, who delight in it after the inward man: and also that which is contained in the Gospel; as that all that the Father had given to Christ should be redeemed by him, that these should be sanctified, and persevere to the end, and be glorified; all which is the good will of God, an acceptable saying to sensible sinners, and such a scheme of salvation as is perfect and complete, and needs nothing to be added to it; and is, by such who are daily renewed in the spirit of their minds, more and more proved, tried, discerned, and approved of, even by all such who have their spiritual senses exercised to discern things that differ.