Sin entered the world through one man, and death through sin, and in this way death came to all people, because all sinned.
Death is the end of sin (Rom. 6:23; James 1:15). Sin has entangled into humanity to such an extent that death is required to rip it out. Sin is a part of humanity’s DNA. You cannot be human and not not sin. In other words, if you are human (and if you are reading this, I assume you are human!), you sin because you are a sinner. You cannot never sin. This is why we must all die; because we are sinners by nature, by our corrupted humanity, by our DNA.
The great Puritan thinker, John Owen, says it this way:
“The body is not only doomed to death by reason of original sin, as death entered upon all on that account; but the body must be brought to death, that sin may be rooted out of it. Sin has taken such a close, inseparable habitation in the body, that nothing but the death of the body can make a separation. The body must be dead because of sin. … Here lies the great mystery of the grave under the covenant of grace, and by virtue of the death of Christ. … A secret virtue shall issue out from the death of Christ unto the body of a believer laid in the grave, that shall eternally purify it, at its resurrection, from every thing of sin.
Be not afraid to enter into darkness: as there is no sting in death, so there is no darkness in the grave. It is but lying so long in the hands of the great Refiner [Jesus}, who will purge, purify, and restore you. Therefore, lie down in the dust in peace.”
And this is why Jesus came, was born of a virgin, lived a perfect life, fulfilled the whole law God required of humanity, paid the penalty of sin by dying on the cross, was raised from the dead on the third day according to the Scriptures, and ascended to the right hand of the Father, and is seated now representing us in Heaven with glorified body.