What causes sickness?

Genesis 3:17-19And to the man he said, “Since you listened to your wife and ate from the tree whose fruit I commanded you not to eat, the ground is cursed because of you. All your life you will struggle to scratch a living from it. It will grow thorns and thistles for you, though you will eat of its grains. By the sweat of your brow will you have food to eat until you return to the ground from which you were made. For you were made from dust, and to dust you will return.”

Romans 5:12When Adam sinned, sin entered the world. Adam’s sin brought death, so death spread to everyone, for everyone sinned.

Sickness and death entered the world when Adam and Eve sinned. From that time on, every human being is born sinful and into a sinful, fallen world, subject to sickness and death.

Romans 8:22-23We know that all creation has been groaning as in the pains of childbirth right up to the present time. And we believers also groan, even though we have the Holy Spirit within us as a foretaste of future glory, for we long for our bodies to be released from sin and suffering. We, too, wait with eager hope for the day when God will give us our full rights as his adopted children, including the new bodies he has promised us.

1 Corinthians 15:43Our bodies are buried in brokenness, but they will be raised in glory. They are buried in weakness, but they will be raised in strength.

Our physical bodies are victim to physical ailments. Our souls are also victim to spiritual ailments. Both of these are a result of human sin. When Christ returns, not only will we be made perfect spiritually, but our bodies will be made new—eternal and free from death and sickness.