Summary: If we are not careful, we can be so tangled up in a long string of religious ideas and rules that we wind up confused and discouraged. Many things about Christianity and the Bible are very complicated, the Gospel is not complicated.
Purpose: To explain the meaning of the Gospel.
Aim: I want the listener to commit (or re-commit) his life to spreading the Gospel and rejoicing in the resurrected Christ.
INTRODUCTION: Life can get very complicated. An illustration of this is a traffic sign at an intersection of two superhighways near Chicago: "To Make a Left Turn Make Two Right Turns." 
Life can get complicated in some very strange ways. "According to the St. Petersburg Times, a thief grabbed some sausages in a meat market but discovered to his sorrow that they were part of a string that was forty-five-feet long. He lost his balance, stumbled over the string, and finally became so entangled that he couldn’t get up to escape. When the police arrived, the thief was still trying to untangle himself from the sausages." 
If we are not careful, we can be so tangled up in a long string of religious ideas and rules that we wind up confused and discouraged.
Many things about Christianity and the Bible are very complicated. Even Peter said: ... just as also our beloved brother Paul, according to the wisdom given him, wrote to you, as also in all his letters, speaking in them of these things, in which are some things hard to understand, which the untaught and unstable distort, as they do also the rest of the Scriptures, to their own destruction. (2 Peter 3:15--16 NAU)
But, the Gospel is not complicated, which makes it even better news.
Paul had been explaining some difficult things to the church at Corinth in this book. He covered issues of Christian liberty, the line of authority in the church, how to take the Lord’s Supper, and how to understand and use our spiritual gifts. Then he comes to chapter 15 and he reminds these Christians about the Gospel --the basic and simple truth about Christianity.
Look at verse one, 1 Corinthians 15:1 Now I make known to you, brethren, the gospel which I preached to you, which also you received, in which also you stand, (NAU) In verse three he said that the Gospel is, "of first importance." Twenty times, in Paul’s letters, he talks about "preaching the gospel" and another 48 times he uses the word "Gospel" without using the word "preach."
The Gospel is the good news about Jesus Christ. If we are not careful, we can complicate the Christian life to the point that we will wonder if we will ever untangle it all. The good news is simply that Jesus died for our sins and is now alive.
"A follower of Buddha wrote this about his leader, ’When Buddha died it was with that utter passing away in which nothing whatever remains.’ Mohammed died at Medina on June 8, 632, at the age of 61, and his tomb there is visited yearly by tens of thousands of Muslims. But they come to mourn his death, not to celebrate his resurrection. Yet the church of Jesus Christ, not just on Easter Sunday but at every service of immersion baptism, celebrates the victory of her Lord over death and the grave." 
As the heart muscle pumps life-giving blood to the whole body, so the resurrection gives life to every part of the Gospel of Jesus Christ.
John 11:25 Jesus said to her, I am the resurrection and the life; he who believes in Me will live even if he dies, (NAU)
In the passage before us today, Paul gives the clearest explanation of what the good news about Jesus Christ is all about.
Vs.1-2 I. The Priority of the Gospel
Vs.1a A. The Gospel is our only message "the gospel"
Romans 1:15-16 15 So, for my part, I am eager to preach the gospel to you also who are in Rome. 16 For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek. (NAU)
We know that the Gospel is powerful because it changes hearts. It changed Paul from a blasphemer of God into a lover of God. The Gospel can change a drug dealer into a church member and a responsible loving dad.
There is nothing else that can turn a selfish person into someone who will love others and willingly give up everything in order to humbly follow Christ.
Vs.1b B. The Gospel is our only choice "which you also received"
Romans 10:9 that if you confess with your mouth Jesus as Lord, and believe in your heart that God raised Him from the dead, you will be saved; (NAU)
Jesus is our only choice. John 6:66-69 66 As a result of this [because Jesus said that salvation was entirely God’s work] many of His disciples withdrew and were not walking with Him anymore. 67 So Jesus said to the twelve, "You do not want to go away also, do you?" 68 Simon Peter answered Him, "Lord, to whom shall we go? You have words of eternal life. 69 We have believed and have come to know that You are the Holy One of God." (NAU)