When Adam sinned in the garden, he was cursed with death.
Genesis 2:17 NKJV
[To Adam] “…but of the tree of the knowledge of good and evil you shall not eat, for in the day that you eat of it you shall surely die.”
Adam passed on his sin to every person that came after him. Whenever someone shares in that sin, they also share in his curse (death). This is why when someone sins today it causes death to work in their body (like sickness, weakness, etc.).
Romans 7:5 NKJV
For when we were in the flesh, the sinful passions which were aroused by the law were at work in our members to bear fruit to death.
It is for this reason that sin is so damaging; not simply because of the physical consequences (drugs kill brain cells, sexual impurity can result in STDs, adultery ruins marriages, etc.). The physical consequences are not the only damage that’s being done.
When Adam’s sin (his cursed sin) works in the body, it’s also working death along with it. It hurts us and our bodies.
Romans 5:12 NKJV
Therefore, just as through one man sin entered the world, and death through sin, and thus death spread to all men, because all sinned…
Using Adam’s sin means using Adam’s curse (death).
Thank God that we have something called forgiveness through Jesus. Jesus’ blood covers sin (makes it as though we have never sinned). And so, when we believe that, it spares us from the death that comes from sin (Exodus 12:13, 2 Peter 1:4).