In Romans 12:2, the Apostle Paul admonishes Christians not to be “conformed to this world: but be transformed by the renewing of [their] mind, that [they] may prove what is that good, and acceptable, and perfect, will of God.” By instructing Christians not to be conformed to “this world”, He was referring to the world system, the way the world operates: its values, principles, standards, habits, manners and style of living, or the world’s moral order which is antagonistic to God. The Bible identifies three predominant principles by which the world and its people operate in 1 John 2:16: For all that is in the world, the lust of the flesh, and the lust of the eyes, and the pride of life, is not of the Father, but is of the world. From here we see a selfish desire for fleshly gratification, an irrespessible desire for possessions and the pride of life.

The people of the world know not God, therefore they live according to the dictates of their depraved minds. But as a Christian, you are a chosen generation, a royal priesthood; therefore, you must walk in the Spirit, governed by the law of God and principles of Christ; you cannot do what your fallen nature suggests, lest you be damned. You cannot do what they do, because their minds are corrupt and deprived of truth 1 Timothy 6:5 Perverse disputings of men of corrupt minds, and destitute of the truth, supposing that gain is godliness: from such withdraw thyself.
You cannot say what they say, because their speech is full of curses, deceit and iniquity Psalm 10:7 His mouth is full of cursing and deceit and fraud: under his tongue is mischief and vanity. You cannot wear what they wear, because the fashions of this world are false and fleeting 1Corinthians 7:31 And they that use this world, as not abusing it: for the fashion of this world passeth away. You cannot conduct business the way they do, because they become wealthy by fraud and unjust gains Proverbs 28:8 He that by usury and unjust gain increaseth his substance, he shall gather it for him that will pity the poor.

You have been called out and set apart from this corrupt, wicked and idolatrous generation, hence you cannot live and work using the same principles and styles promoted by the world. There must be a clear distinction between you and the world. You cannot go with the flow; you cannot flow with the tide or bend to it. Others may do as they please, you cannot. You have been bought with a price and you are not your own. You must do as God pleases because the love of God constrains us, so that we who are alive should no longer live for ourselves but for the One who died and rose for our justification 2 Corinthians 5:14 For the love of Christ constraineth us; because  we thus judge, that if one died for all, then were all dead: 15 And that he died for all, that they which live should not henceforth live unto themselves, but unto him which died for them, and rose again.

Conformity to the world makes you a friend of the world, and friendship with the world makes you an enemy of God James 4: 4 Ye adulterers and adulteresses, know ye not that the friendship of the world is enmity with God? whosoever therefore will be a friend of the world is the enemy of God. Worldliness will darken your mind, make you insensitive to the things of God and and alienate you from the life of God Ephesians 4: 18 Having the understanding darkened, being alienated from the life of God through the ignorance that is in them, because of the blindness of their heart: The scripture is clear, there is no middle ground; you cannot walk hand-in-hand with God and the world. To love God is to denounce the world, and to love the world is to be an enemy of God I John 2:15 Love not the world, neither the things that are in the world. If any man love the world, the love of the Father is not in him.

As a Christian, you must be sober and vigilant at all times, and be wary of the world and its subtle enticement 1 Peter 5:8 Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour: The devil is constantly cooking up seemingly harmless looking vices to entice Christians and pressure them into blending with the world. While you still live in the world, you are not of the world John 15:19 If ye were of the world, the world would love his own: but because ye are not of the world, but I have chosen you out of the world, therefore the world hateth you.
John 17:16 They are not of the world, even as I am not of the world. You must not be absolved in its evil and sinfulness. Rather, you must consciously, consistently and resolutely renounce it. You should also be “transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect will of God” Romans 12:2. Transformation comes by Christ, His word, and His way. It is the way to continuously remain unspotted from the corruption of the world.
Examine your life today. Are you already mingling with the world and conforming to its practices? The Lord is calling you back to Himself. Repent from your sins and return to Him.