1 Corinthians 1:26

For ye see your calling, brethren, how that not many wise men after the flesh, not many mighty, not many noble, are called (KJV)

Then: Called to be Christians, the Corinthians are bickering over who had the greatest preacher. Fitzmyer calls that a scandal (p. 136 & 151). He sees verses 18-21 as showing the impact (which Paul identifies) within the church and its public reputation as two problems. The self-status of the Corinthians is putting the church at risk. Paul needed them to go back and reevaluate their individual personal relationships to the Christ who had died for their sin. Without Christ were they wise? Mighty? Noble? That's the starting point for individuals and for groups wanting to serve the Lord.

Now: If you only stick with the personal message of Paul's letter, everything he says relates to a believer's spiritual growth. If you broaden it to local congregations, parts of Paul's letter apply to one season of a church's growth and parts to another. Everything Paul says can be taken as warnings. Be on the lookout for the church's reputation in a community. Be on the lookout for interpersonal relations within a congregation. Always remember Christ, who he was, what he did, and his love for us. Growth follows.

Joseph A Fitzmyer First Corinthians: a new translation with introduction and commentary (New Haven CT: Yale University Press, c2008). http://books.google.com/books?id=W3b-mWk1SxoC&dq=Corinthians+introduction&printsec=frontcover&source=bl&ots=fMjYisa8HV&sig=5Pr-s91r1P4zUIBQyyXFDX6IlP8&hl=en&ei=uqUBS76pK9KGlAfEg52ZCw&sa=X&oi=book_result&ct=result&resnum=6&ved=0CBQQ6AEwBThG#