John 3:20 King James Version (KJV) 20 For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved.
When a person who is living in sin comes in the presence of someone who is holy, they feel uncomfortable. In some cases they may even get mad. The walk of holiness causes one to stand out. The light is shining to call one to repentance.