1 Corinthians 2:12

Now we have received, not the spirit of the world, but the spirit which is of God; that we might know the things that are freely given to us of God (KJV)

Then: Paul hops back to his main topic of wisdom (Fitzmyer, p. 181 - 2:10-11 are a digression). Men know God's wisdom when his spirit is in them - not the spirit of the world. The connection starts at conversion, and enables a closeness with God (Baker, p. 49). Before the resurrection, only a few designated individuals could speak with the conviction of having God's direction. Now all believers and followers of Christ have access to his wisdom.

Now: Secular vs. Spiritual. With the Spirit's presence, we pay attention to words proceeding from our mouths, thoughts which tear down or build up others, ideas which can bring peace and hope to friends and neighbors. No more is life a "me first" kind of thing. The Spirit shows ways to "Love one another" and increase the kingdom of God. Paul helps us understand and expect to use the knowledge and wisdom coming into our lives.

Extra Source: 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+and+Fitzmyer&printsec=frontcover&source=bl&ots=fMkQjo3eGY&sig=MB1oT-4Ir0uoDeiFJ8C7J9oum2I&hl=en&ei=k_sgS_CYKc6SlAeRv6z3CQ&sa=X&oi=book_result&ct=result&resnum=6&ved=0CBgQ6AEwBQ#v=onepage&q=&f=false
Cornerstone Biblical Commentary 1 Corinthians (William Baker), 2 Corinthians (Ralph Martin & Carl Toney), ed. by Philip Comfort. Carol Stream: Tyndale House Publishers, c2006.