From Paul, in 1 Corinthians 15:
Christ died for our sins, just as the Scriptures said. He was buried, and he was raised from the dead on the third day, just as the Scriptures said. He was seen by Peter and then by the Twelve. After that, he was seen by more than 500 of his followers at one time, most of whom are still alive, though some have died. Then he was seen by James and later by all the apostles. Last of all, as though I had been born at the wrong time, I also saw him. For I am the least of all the apostles. In fact, I’m not even worthy to be called an apostle after the way I persecuted God’s church.
But whatever I am now, it is all because God poured out his special favor on me—and not without results. For I have worked harder than any of the other apostles; yet it was not I but God who was working through me by his grace. So it makes no difference whether I preach or they preach, for we all preach the same message you have already believed.
But tell me this—since we preach that Christ rose from the dead, why are some of you saying there will be no resurrection of the dead? For if there is no resurrection of the dead, then Christ has not been raised either. And if Christ has not been raised, then all our preaching is useless, and your faith is useless. And we apostles would all be lying about God—for we have said that God raised Christ from the grave. But that can’t be true if there is no resurrection of the dead. And if there is no resurrection of the dead, then Christ has not been raised. And if Christ has not been raised, then your faith is useless and you are still guilty of your sins. In that case, all who have died believing in Christ are lost! And if our hope in Christ is only for this life, we are more to be pitied than anyone in the world.
But in fact, Christ has been raised from the dead. He is the first of a great harvest of all who have died.
So you see, just as death came into the world through a man, now the resurrection from the dead has begun through another man. Just as everyone dies because we all belong to Adam, everyone who belongs to Christ will be given new life. But there is an order to this resurrection: Christ was raised as the first of the harvest; then all who belong to Christ will be raised when he comes back.