What is disease?
Biological change in the health status of a being (man, animal, etc.), manifested by a set of perceptible symptoms or not; sickness, evil, disease. "cancer is a difficult disease to cure".
2. BY EXTENSION
Alteration of the mood or mood of a being.
What does the Bible say about diseases?
The Bible speaks of diseases, pests, epidemics and pandemics basically as things that result from the curse of sin. This means that ultimately the root of the illnesses that affect men is their spiritual illness.
When God created the world, the Bible says that He saw that everything was very good (Genesis 1). This means that diseases were no part of the original creation. But when man transgressed God's will, divine justice - which is perfect and holy - demanded punishment for disobedience. This disobedience brought terrible consequences not only to man, but to all creation (Romans 8:22). Under the divine curse, creation has become dysfunctional. Illness, and consequently physical death, results from this imbalance.
So be it chronic or acute diseases, be it small outbreaks or big pandemics of infectious diseases, in the end they all point to the reality of man's sin.
Assuming that the basic cause of the existence of diseases is sin, that is, diseases are consequences of the curse that fell on creation because of man's disobedience, the Bible delves a little deeper into this issue and shows some more reasons specific to diseases.
Many illnesses are caused by sheer lack of health care. But the Bible says that it is sometimes possible that the cause of an illness is an individual sin. In that sense, illness can be as much a direct consequence of that sin as it is a punishment for that sin. A person can contract a serious illness due to his sinful lifestyle; or you may suffer from a painful illness as a punishment for your recurring sin. Once Jesus healed a sick man and told him: "See, you are well! Sin no more, that nothing worse befall you." (João 5:14).
But it is important to emphasize that not all illnesses are due to an individual sin. It was very easy for Jews to relate all kinds of illness to a person's individual sin. But the Lord Jesus made it clear that this is not always the case (John 9:3).
The Bible also shows that there is a possibility that an illness is associated with the action of evil spirits. During his earthly ministry, the Lord Jesus delivered and healed people who lived in that situation (examples Matthew 12:22; Luke 13:11).
Finally, it is not uncommon for diseases to have an educational purpose. In his providence, God can use sickness to develop faith and perfect the character of His children. In that sense, illness is a blessing and not a curse for the believer - even if he or she does not understand how this can be possible.
The pious Job is one of the clearest examples in the Bible of someone who was afflicted by a disease that had a pedagogical purpose. Also if we understand that the thorn in Paul's flesh was a physical disease - as the original Greek expression seems to favor - then we have another well-known example of how God uses a disease to prove and teach someone (2 Corinthians 2:7).
An excellent preventive medicine is to follow God's plan. The Bible says in Exodus 15:26 saying, "If you will diligently hearken to the voice of the LORD your God, and do that which is right in his eyes, and give heed to his commandments and keep all his statutes, I will put none of the diseases upon you which I put upon the Egyptians; for I am the LORD, your healer."
Worship of God frees us from disease. The Bible says in Exodus 23:25 "You shall serve the LORD your God, and I will bless your bread and your water; and I will take sickness away from the midst of you."
Jesus has the power to heal diseases. The Bible says in Matthew 4:23-24 "And he went about all Galilee, teaching in their synagogues and preaching the gospel of the kingdom and healing every disease and every infirmity among the people. So his fame spread throughout all Syria, and they brought him all the sick, those afflicted with various diseases and pains, demoniacs, epileptics, and paralytics, and he healed them."
Healing comes from the Lord. The Bible says in Jeremiah 17:14 "Heal me, O LORD, and I shall be healed; save me, and I shall be saved; for thou art my praise." In order to be healed of disease, follow God's plan. The Bible says in James 5:14-16 "Is any among you sick? Let him call for the elders of the church, and let them pray over him, anointing him with oil in the name of the Lord; and the prayer of faith will save the sick man, and the Lord will raise him up; and if he has committed sins, he will be forgiven. Therefore confess your sins to one another, and pray for one another, that you may be healed. The prayer of a righteous man has great power in its effects."
There will be no disease in heaven. It is in the Bible, Isaiah 33:24 "And no inhabitant will say, "I am sick"; the people who dwell there will be forgiven their iniquity."