Why do we still have physical death?
The reason for death is because sin entered the world through Adam. When Christ died on the cross to pay for our sins and free us of the power of sin, why do we not have eternal life on earth once we believe that He is The Life, The Way, and The Truth?
For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
Al Mari
Humans were created "matter-composed"(from dust, earthy), not "spirit-composed". As matter, man is mortal and can die, unlike "spirit-body" that is immortal. We were created as an "image" (Gen. 1:27) of the immortal God, although "matter-composed" we will be "like him" (I John 3:2), in the future, spirit-body and immortal. The "image" is "earthy", meaning from dust or earth and unlike man-Jesus "from above" (I Cor. 15:46-48), who came from heaven and not formed on earth nor of " dust of the ground". But, at resurrection Paul states that we will change into immortality (I Cor. 15:51-57), "spirit-composed body", like Jesus' body post resurrection.
Sin did not need to be committed for us to die. Genesis 2:17 does not refer to 1st death that is "physical" and has resurrection, but to "eternal death", wherein there is no more resurrection. All humans will die as man-Jesus died but resurrected "spirit-bodily". Anyone who got resurrected to physical body (as Lazarus and others" John 11:14; Lu.7:15; 8:51-56;Acts 9:40-41;20:9-12) and died again, will again experience resurrection, whether to life or judgment. There is a first and second (or 3rd) resurrection as there is first and eternal death. See Rev. 20:4-6, v-14).
Meanwhile, the Spirit of God (Jn 16:7-8) that was promised by the Father after Jesus' death and resurrection, will "in-dwell" to humans as it did to the apostles and others at Pentecost for the purpose of (v-6) "will reprove (elencho/rebuke) the world of sin, and of righteousness, and of judgment". The spirit will also help us discern spiritual things (I Cor.2:14-16), as eyeglasses help poor vision and hearing aids for poor hearing (Matt. 13:9-17; Mk. 4:9; Rev. 3:22), "empower" us "to heal the sick, raise the dead, etc." and express the "fruits of the Spirit"(Gal. 5:22-23).
This is the "spirit" guiding us to follow the Law, "written" by this Spirit (2 Cor. 3:3) in the "fleshly tables of our heart(mind)", not in "tables of stone" and as promised, the "new covenant" (Heb. 8:7-13). This Spirit is giving us the "mind of Christ" (Phil. 2:5-11), so we will be "one" with him as he is "one" with the Father (John 17:21).