What causes disease and illness?

Disease and illness are a consequence of sin entering the world.  God told Adam that he would die if he ate of the tree of knowledge, and he did so anyways (Genesis 2:17; 3:6).  Even though sin is the cause of disease, it is not primarily the reason someone has contracted it.  The Bible tells us that life happens to everyone, no matter good or evil, just or unjust (Matthew 5:45).  Many times in the Bible people associated a person’s illness to a sin they may have committed but wrongfully so, as with the blind man in John 9.  Remember, we are to rejoice in the good times and the bad, in health and in sickness (2 Corinthians 12:10).  Keep your eyes on God and your mouth covered.