2Co 5:21 For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him. This has a twofold meaning. Others have well pointed out that he took our sin upon him for reconciliation (v19-20), but in the surrounding verses, Paul also tell us what he told us in other epistles as well. That we are dead to sin by the body of Christ that was crucified so that the body of sin would be destroyed, because sin brings forth death. He crucified our flesh from which lusts comes, therefore we being dead, are free from sin and dead to sin. He died with and for our sin so we could die to sin (v14).
2Co 5:10 For we must all appear before the judgment seat of Christ; that every one may receive the things done in his body, according to that he hath done, whether it be good or bad. Here, Paul warns of judgment for sin (contrasting good or bad -think good and bad tree). Then he says 'we are made manifest to God', which would be the good as opposed to bad. Think 'fruit unto holiness'. This he says is an answer to those that are religious hypocrites. The gospel can do what the law could not -free man from sin because the body of sin was crucified. This is accomplished in the same act of Christ taking sin to the cross. It is forgiveness of sin and victory over sin for those that walk by faith in what Christ has done for us and to us. Christ and him crucified, with us in him.
2Co 5:11 Knowing therefore the terror of the Lord, we persuade men; but we are made manifest unto God; and I trust also are made manifest in your consciences.
2Co 5:12 For we commend not ourselves again unto you, but give you occasion to glory on our behalf, that ye may have somewhat to answer them which glory in appearance, and not in heart.
2Co 5:14 For the love of Christ constraineth us; because we thus judge, that if one died for all, then were all dead: Don't receive the complete and finished work of Christ in vain. Be a good tree that bears good fruit. Don't be as those that glory in appearance.
2Co 5:15 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.
2Co 5:16 Wherefore henceforth know we no man after the flesh: yea, though we have known Christ after the flesh, yet now henceforth know we him no more.
2Co 5:17 Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new.
2Co 5:21 For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him.
2Co 6:1 We then, as workers together with him, beseech you also that ye receive not the grace of God in vain.
2Co 6:14 Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?
2Co 6:15 And what concord hath Christ with Belial? or what part hath he that believeth with an infidel?
2Co 6:16 And what agreement hath the temple of God with idols? for ye are the temple of the living God; as God hath said, I will dwell in them, and walk in them; and I will be their God, and they shall be my people.
2Co 6:17 Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you.
2Co 6:18 And will be a Father unto you, and ye shall be my sons and daughters, saith the Lord Almighty.