In 1 Corinthians 1:18 Paul said, "For the word of the cross is to those who are perishing foolishness, but to us who are being saved it is the power of God." Then in verses 22-24 he said, "Since Jews indeed ask for signs and Greeks seek wisdom, but we preach Christ crucified, to Jews an offense, and to the nations foolishness, but to those who are called, both Jews and Greeks, Christ, God's power and God's wisdom." These verses indicate the centrality and universality of Christ's death and resurrection in God's economy. For this reason, in 1 Corinthians 2:2 Paul said, "For I determined not to know anything among you except Jesus Christ, and this One crucified."
The cross of Christ is the centrality and universality of the way of the Christian life (1 Cor. 1:18, 22-24; 2:2). The way of the Christian life is the way of the cross. Christ's cross is the centrality and universality of our way to live the Christian life. The way to live the Christian life is composed of and constituted with Christ's death.
All the descendants of Adam are living to die. Eventually, everyone enters into a tomb. The unbelievers die and enter into a physical tomb, but the believers die by entering the cross. The cross is the "tomb" of the believers. The unbelievers die just to die, but we believers die to be resurrected. The physical tomb into which the unbelievers enter has only one opening, an entrance. But the tomb of the cross into which the believers enter has two openings, an entrance and an exit. We enter through one opening and leave through another opening. Hence, the cross is a place of transit between our place of origin and our destination. If someone were to travel by plane from Los Angeles to Taipei, he may have a stop in Hawaii on his trip. Hawaii would be a place of transit between Los Angeles and Taipei. The passenger on the plane who made a stop in Hawaii would be called a passenger in transit. We believers are "passengers in transit." We enter into the tomb of the cross by death and go out into resurrection. The cross is our place of transit. To enter the tomb of the cross is to die, and to get out of the tomb of the cross is to be resurrected. Hence, the cross, which is the death of Christ, is the centrality and universality of the way for us to live the Christian life.