1 Corinthians 15

3 This is the core of Christian faith, and this is what makes it unique among all the religions of the world. Jesus, the Son of God, and the Messiah died for sins. Everyone who believes and obeys Jesus is completely forgiven.
4 Death is not the end of the story, though. Jesus rose from the dead. His resurrection gives us hope that we, too, will be raised from the dead and that full justice will be served. All this was predicted ahead of time, so we can verify much of Jesus' ministry by finding references to it dating up to the time of creation.
5 The reason we know this is that Jesus appeared alive to hundreds of witnesses. In Paul's day, the listeners would have had the opportunity to verify the Gospel with eyewitnesses. Today we have this witness recorded in the Bible.
42 The only body a person knows in this lifetime is the "natural" body he inherited from his parents. This body is amazing and beautiful in its own right, but it will ultimately prove to be perishable. Because our natural bodies are contaminated by sin, they will die. However, after a persons' natural body dies, he will receive a resurrected body that will not die.
43 The natural body is subjected to the effects, uncertainty, and humiliation of this sinful world. The weakness of the body is most easily seen in infants, the very old, those who are maimed, those who are ill, and those who die. The resurrected body will not suffer any of these consequences because it will not be contaminated by sin.
44 The natural body is the one we receive from our parents. Inherited genetic disorders show one way that we inherit the weaknesses of our parents' bodies. The spiritual (i.e., resurrected) body is one we will receive from God. Since God is perfect, we can expect to receive bodies without flaws.

The term "spiritual body" is used here, and this brings to mind the idea of people becoming ghost-like in the afterlife. However, the term "body" here is the same for the natural and spiritual bodies, which could lead us to the conclusion that our spiritual bodies will be physical bodies. The term "spiritual," then, refers to the origin of the body, not its substance. There are many other passages in the Bible that indicate that the afterlife will be physical (Isa 11:6-9, Rev 21:1-4).

45 To explain the origin of the natural body, Paul returns to Gen 2:7. The origin of the spiritual body is with Jesus.
46 For people, the physical life comes first when we are born. The spiritual birth can only happen with an informed and conscious decision to have faith in Jesus.
48 The natural body comes from dust and returns to dust. The spiritual body comes from God and will eternally remain with Him.
49 People are easily distinguishable from animals because of our shape. This is because we inherit similar genetic "blueprints" from our parents and ancestors, all the way back to Adam and Eve. We bear the image of God, but that image is marred by sin. Our resurrected bodies will be free from sin and flaws, and we will then accurately bear the image of God as we were intended to do.