C. S. Lewis on The Resurrection

In his book, "Miracles", C. S. Lewis makes the following assertion.

The Resurrection is the central theme in every Christian sermon reports in the Acts. The Resurrection, and its consequences were the "gospel" or good news which the Christian brought: what we call the 'gospels,' the narratives of Our Lord's life and death, were composed later for the benefit of those who had already accepted the gospel. They were in no sense the basis of Christianity: they were written for those already converted. The miracles of the Resurrection, and the theology of that miracle, comes first: the biography comes later as a comment on it. Nothing could be more unhistorical than to pick out selected sayings of Christ from the gospels and to regard those as the datum and the rest of the New Testament as a construction upon it. The first fact in the history of Christendom is a number of people who say they have seen the Resurrection. (C.S. Lewis, Miracles. pgs. 143,144).

In the first sermon in Acts, Peter focused on the resurrection.

Brothers, I may say to you with confidence about the patriarch David that he both died and was buried, and his tomb is with us to this day. Being therefore a prophet, and knowing that God had sworn with an oath to him that he would set one of his descendants on his throne, he foresaw and spoke about the resurrection of the Christ, that he was not abandoned to Hades, nor did his flesh see corruption. This Jesus God raised up, and of that we all are witnesses. (Acts 2:29-32 ESV)

Paul preached the resurrection so often, his hearers sometimes thought he was talking about two deities:

So he reasoned in the synagogue with the Jews and the devout persons, and in the marketplace every day with those who happened to be there. Some of the Epicurean and Stoic philosophers also conversed with him. And some said, “What does this babbler wish to say?” Others said, “He seems to be a preacher of foreign divinities”—because he was preaching Jesus and the resurrection." (Acts 17:17-18 ESV)

Later in Acts 17, as Paul preached, We see some of the philosophers of Athens, like the liberal Christians today, reject the resurrection,
"Now when they heard of the resurrection of the dead, some mocked. But others said, “We will hear you again about this." (Acts 17:32)

I wrote once on an old website that no one preaches the Resurrection anymore. One person responded that there is nothing about the resurrection to preach. However Paul celebrates the resurrection,

and what is the immeasurable greatness of his power toward us who believe, according to the working of his great might that he worked in Christ when he raised him from the dead and seated him at his right hand in the heavenly places, far above all rule and authority and power and dominion, and above every name that is named, not only in this age but also in the one to come. (Ephesians 1:19-21 ESV)

that I may know him and the power of his resurrection, and may share his sufferings, becoming like him in his death, that by any means possible I may attain the resurrection from the dead. (Philippians 3:10-11 ESV)

What shall we say then? Are we to continue in sin that grace may abound? By no means! How can we who died to sin still live in it? Do you not know that all of us who have been baptized into Christ Jesus were baptized into his death? We were buried therefore with him by baptism into death, in order that, just as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life. For if we have been united with him in a death like his, we shall certainly be united with him in a resurrection like his.(Romans 6:4-5 ESV)

For he was crucified in weakness, but lives by the power of God. For we also are weak in him, but in dealing with you we will live with him by the power of God. (2 Corinthians 13:4 ESV)

Understanding the power of the resurrection is key to living a resurrected life.