For as in Adam all die, even so in Christ all shall be made alive.
This chapter—1 Corinthians 15—is often known as the Resurrection Chapter. Partly to combat the teachings of some who didn’t believe in the resurrection (verse 12), Paul showed the reality of Jesus Christ’s resurrection and how it demonstrated God’s power and willingness to resurrect everyone else.
Adam was the forerunner of the whole human race, and his choice to eat the fruit of the tree of the knowledge of good and evil anticipated the choice all human beings have made since. That choice was sin, which leads to death. God had told Adam that if he ate of the forbidden fruit, “You shall surely die” (Genesis 2:17).
But Jesus Christ came to solve the problem of human sin and death. He gave His life to pay the penalty of sin in our stead, making it possible for us to repent and be forgiven. Then He was resurrected, becoming the forerunner of all human beings who will live again.
All will come back to life, but not all at the same time (1 Corinthians 15:23) and not all will be given eternal life. Daniel 12:2 explains that all who are in the grave will be resurrected, “some to everlasting life, some to shame and everlasting contempt.” We hope and pray that latter group is a very small one.
Read more about the resurrections in the article “Resurrections: What Are They?”