1 Corinthians 15:16

For if the dead rise not, then is not Christ raised (KJV)

Then: In the previous verses, Paul worked with the main concerns of the apostles (teachers) if there were no resurrection. With this verse he turns to the main concerns of all believers if there be no resurrection (Baker, p. 219). Those consequences are the worst. If the dead don't rise, that is if the dead can't rise, then it did not happen with Christ. Corinthians need to understand what that means to their personal faith and their destiny as human beings.

Now: Commentators are all over the map in discussing this passage - rhetorical organization, physical and spiritual ideas of resurrection, Paul's personal relationship to the content, God's purpose in resurrection, etc (Thiselton, p. 1169-1181). The more one reads, the more important it is to return to Paul's succinct presentation. The logic in this verse is simple. If true, its implications lead to nothingness. Those who know the Christ immediately know its theoretical implausibility. Even the idea of Christ's not being resurrected trashes all that is known about God's original plan in the Garden to allow people a way of escape. ("He shall bruise thy head," Geneis 3:15).

Extra Source: Cornerstone Biblical Commentary 1 Corinthians (William Baker), 2 Corinthians (Ralph Martin & Carl Toney), ed. by Philip Comfort. Carol Stream: Tyndale House Publishers, c2006.
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