"Absent in Body," "Present in Spirit" - 1 Corinthians 5:3

For I verily, as absent in body, but present in spirit, have judged already, as though I were present, concerning him that hath so done this deed (KJV)

Then: Paul has already judged the deed as abhorrent. He didn't need to be there physically. The church which was present should not have needed any admonitions. They should have done it without him. Time was wasting.

Now: Commentators focus on the full meaning of "absent in body/present in spirit." Thiselton (p. 392) discusses grammatical difficulties. He emphasizes that the phrases have the actual meaning of Paul's not being on site at Corinth. His spirit, evidenced through his guidance and teachings in the letter, allow for one kind of presence in Corinth. Paul's heart and yearning for the Corinthians' eternal security define another kind of spiritual presence. In addition, the phrases, "absent in body/present in Spirit," also relate to the theological sense of Christ's being absent in body and present in Spirit. Paul assumes (takes on) Christ's authority as he speaks the Lord's concern, knowledge, teachings and desires for the church. Thus, he has authority to the point of putting someone out of church fellowship. Fee (p. 213) clarifies the intent is to send the transgressor into an environment where he will recognize the difference between the domain of Satan and the domain of Christ. Subsequently, he has opportunity to repent and rejoin the kingdom. All these understandings and principles guide today's church.

Extra source: The First Epistle to the Corinthians: a commentary on the Greek text by Anthony C. Thiselton (Authentic Media, c2000) online at http://books.google.com/books?id=IHG_DNLpmroC&dq=1st+Corinthian+commentaries&printsec=frontcover&source=in&hl=en&ei=W9fQSpC1GILplAfHiumoCg&sa=X&oi=book_result&ct=result&resnum=11&ved=0CB8Q6AEwCg#v=onepage&q=&f=false
The First Epistle to the Corinthians by Gordon D. Fee (Eerdman's 1987) online at http://books.google.com/books?id=XlBp10nUTXAC&dq=Gordon+Fee+Bible+commentator&printsec=frontcover&source=in&hl=en&ei=SwLNSu3nA4v6Mf2XlDo&sa=X&oi=book_result&ct=result&resnum=12#v=onepage&q=&f=false