The apostle Paul wrote in I Corinthians 1:18-25:
"For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God. For it is written: 'I will destroy the wisdom of the wise, and bring to nothing the understanding of the prudent.' Where is the wise? Where is the scribe? Where is the disputer of this age? Has not God made foolish the wisdom of this world? For since, in the wisdom of God, the world through wisdom did not know God, it pleased God through the foolishness of the message preached to save those who believe. For Jews request a sign, and Greeks seek after wisdom; but we preach Christ crucified, to the Jews a stumbling block and to the Greeks foolishness, but to those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God. Because the foolishness of God is wiser than men, and the weakness of God is stronger than men."
In those verses Paul referred to the message of the cross and the fact that he preached "Christ crucified." If you continue reading, you'll discover in 2:2 that Paul declared his determination not to know anything among them "except Jesus Christ and Him crucified." Clearly, Paul was focused intently on Jesus and His suffering on the cross.
But what did Paul mean by saying that he didn't want to know anything among them "except Jesus Christ and Him crucified"? Did he mean that he only wanted to preach and learn exclusively about Jesus' death on the cross? I don't believe so, or else he wouldn't have written about marriage, child rearing, government, miraculous gifts, and a host of other topics. I believe Paul was trying to articulate the fact that he would not waste time declaring the philosophies of men or the wisdom of this world. He was not interested in entertaining people but in saving them. His preaching would touch on a number of themes, but they all were connected to Jesus, the scheme of redemption, or how to live as a Christian.
A consideration of the kind of preaching that was done by all the inspired preachers in the New Testament will quickly reveal that the cross of Christ was the center of their preaching. You can see this in:
Notice that in each of these cases, the emphasis of the preaching is on the death, burial, and resurrection of Jesus. We all need to understand that Jesus had to die in order to satisfy divine justice. The problem that God had to deal with was that he wanted man to be forgiven, but His perfect sense of justice would not allow Him to simply overlook man's sin--at least not forever. Romans 3:24-26 underscores this problem and its solution - "Being justified freely by His grace though the redemption that is in Christ Jesus, whom God set forth as a propitiation by His blood, through faith, to demonstrate His righteousness, because in His forbearance God had passed over the sins that were previously committed, to demonstrate at the present time His righteousness, that He might be just and the justifier of the one who has faith in Jesus." Those verses contain the answer as to why Jesus had to die; namely, to demonstrate God's righteousness in forgiving sin. But, that leaves some other questions: Why the cross? Why such agony and shame? Why should we preach Jesus Christ and Him crucified? There are many answers, and we will consider some of them over the next couple lessons.