Parsing Corinthians Chapter 5

This is a chapter where Paul talks about how radically different your outlook on life and your priorities become when you convert to Christ. 

He says that such conversion transforms what we hope for and yearn for.  We begin to yearn to be part of heaven here; to become one with God in his work.

And that transformation is effectuated by God as we experience the influence of the Holy Ghost.  (Paul likens our experience with the Holy Ghost to "earnest" money--money given to show one's sincere determination to give all that was promised in a contract.  Our experience with the Holy Ghost can be seen as receiving an "earnest" outlay and taste of the light and power of God, the clear reality of God, God's work, and all that is promised and intended for his children, both now and in the future, by the Father and the Son.)

The "selfsame thing" refers to our yearning to live a holy, heaven directed life.

Just as we are more inclined to move forward with faith in a legal contract with another person when that person has given us earnest money, which money indicates full intent to give the whole sum which we have not yet had presented to us, so we move forward with faith in a covenant with God having experienced the "earnest" he presents to us; the power of the Holy Spirit in our lives.  Thus the verse in this chapter:   "we walk by faith" (having received a taste of what it is like to be fully connected with God and having faith that a complete connection is possible), "not by sight" (not yet having seen or received the fullness of what is promised).

Previously to this our focus was on ourselves and working on our own behalf ("live unto themselves") but that changes and we become more interested in working for and with God the Father and his son Jesus Christ.

Thus we become a new person "in Christ", becoming "a new creature", born again and also reconciled to God because we have begun to understand and embrace Christ's atonement (his taking on our sins and paying the price for them so that we may hope to be one with Him and holy and love-filled too).

And, says, Paul, that gift of the atonement, that "reconciliation" is a thing that is not only given, but also must be actively welcomed and received in order for our transformation to begin as well as to come to full fruition.

"We pray you in Christ's stead, be ye reconciled to God.  For he that made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him."