In a curious passage, Paul links the resurrection with preaching and preaching with resurrection:
Now I would remind you, brethren, in what terms I preached to you the gospel, which you received, in which you stand, by which you are saved….. For I delivered to you as of first importance what I also received, that Christ died for our sins in accordance with the scriptures, that he was buried, that he was raised on the third day in accordance with the scriptures and that he appeared….Now if Christ is preached as raised from the dead, how can some of you say that three is no resurrection of the dead? But if there is no resurrection of the dead, then Christ has not been raised; if Christ has not been raised, then our preaching is in vain and your faith is in vain. (1 Corin. 15:1, 3-5, 12-14)
Some at Corinth are denying the resurrection. What proof do they have that Jesus truly arose from the dead and appeared to his first followers? In response, Paul says that they know that Christ is raised because that’s what Paul preached to them. Is that all? Listen to Paul’s logic, “I have preached to you that Christ is raised from the dead. Now if I preached that how can some of you say there is no resurrection of the dead?”
Paul goes on to say, in effect, “Now if there is no resurrection of the dead, then Christ has not been raised and that would mean that, when I preached, I lied and that your faith is in vain. But I did tell the truth in my preaching and just to prove it, I’m going to preach it to you again. Christ has been raised from the dead.'” There.
Tom Long asks, What sort of circular, merry-go-round logic is this? We want proof of Easter and all Paul gives us is more preaching? “I told you about the resurrection. You don’t believe in the resurrection? Let me tell you about the resurrection,”  Logicians says this is an “if this-then this” sort of logic. If X is true, then Y must be true. Such arguments are dependent upon their ability to touch down somewhere in irrefutable human experience. The first proposition must be true. If not, the second proposition is false. If X is not irrefutably true, then there is no way that Y can be true.
This logic moves from what we don’t know for sure back to what we know for certain, rippling back toward affirmation.
Thus reasons Paul:
If there is no resurrection of the dead…
…then Christ has not been raised.
And if Christ has not been raised…
…then our preaching was a lie
And if our preaching was a lie…
…then your faith is futile.
At this point, I think Paul expected the gathered Corinthians to shout in unison, “But our faith is not futile.” The Corinthians may have had problems with love (I Corinthians 13), with getting along with each other in the church, but they had faith — spoke in tongues, worried about eating meat offered to idols, had knock down drag outs over baptism. They were just chock full of faith. Nobody could argue over their experience of Easter. Paul implies that the Corinthians were so full of faith, so dazzled by the resurrection that, when he preached to them, he was forced to preach Jesus Christ and him crucified in an attempt to get them back down to earth for a few moments. Anybody who worshipped at one of their Sunday evening free-for-alls might go away thinking that Christians were weird, out of control, but nobody could deny that some life-giving power had been unleashed among them.
So let’s reverse the order:
Because your faith is not futile,
Our preaching was not a lie,
Christ has been raised,
There is resurrection of the dead.
“Because your faith is not futile….There is resurrection of the dead.” It’s an important truth. Easter begins to dawn, not in the preacher’s assembling alleged “evidence” from history. The dry reconstruction of historians will not get us to resurrection. Easter begins in the recognition that our faith is not futile, in our present experience of the Risen Christ roaming among us. It is the testimony, not just of preachers like me, but of countless believers like you, that is the evidence. When bread and wine touch your lips and you see, feel the real presence. When you thought your heart would break in disappointment and pain, but it didn’t because He was standing beside you in the dark. When you didn’t know what to say and there were just the right words, words not of your own devising, being spoken by you. When you dragged into the church, cold at heart, skeptical, and distant, yet at the hymns, your spirit rose to greet His, your faith is not in vain.
This is the logic of Easter.
 Thomas G. Long, The Senses of Preaching, pp. 92-93.