And be not conformed to this world.
If a Christian can by possibility be saved while he conforms to this world, at any rate it must be so as by fire. Such a bare salvation is almost as much to be dreaded as desired. Reader, would you wish to leave this world in the darkness of a desponding death bed, and enter heaven as a shipwrecked mariner climbs the rocks of his native country? then be worldly; be mixed up with Mammonites, and refuse to go without the camp bearing Christ's reproach.
But would you have a heaven below as well as a heaven above? Would you comprehend with all saints what are the heights and depths, and know the love of Christ which passeth knowledge? Would you receive an abundant entrance into the joy of your Lord? Then come ye out from among them, and be ye separate, and touch not the unclean thing. Would you attain the full assurance of faith? you cannot gain it while you commune with sinners. Would you flame with vehement love? your love will be damped by the drenchings of godless society.
You cannot become a great Christian - you may be a babe in grace, but you never can be a perfect man in Christ Jesus while you yield yourself to the worldly maxims and modes of business of men of the world. It is ill for an heir of heaven to be a great friend with the heirs of hell. It has a bad look when a courtier is too intimate with his king's enemies. Even small inconsistencies are dangerous. Little thorns make great blisters, little moths destroy fine garments, and little frivolities and little rogueries will rob religion of a thousand joys.
O professor, too little separated from sinners, you know not what you lose by your conformity to the world. It cuts the tendons of your strength, and makes you creep where you ought to run. Then, for your own comfort's sake, and for the sake of your growth in grace, if you be a Christian, be a Christian, and be a marked and distinct one.