“…in the day when God will judge the secrets of men by Jesus Christ, according to my gospel.” (Romans 2:16).
The Scriptures solemnly emphasize the thoroughness of God’s knowledge of every inhabitant on this earth. He knows when every sparrow dies (Matthew 10:29). He knows the number of hairs on every head (Matthew 10:30). There is not a single bone of any skeleton hidden in your closet of secrets of which He is ignorant.
Because of this, Jesus Himself told His disciples, “For there is nothing covered that will not be revealed, and hidden that will not be known. Whatever I tell you in the dark, speak in the light; and what you hear in the ear, preach on the housetops” (Matthew 10:26-27). On another occasion, He solemnly warned His disciples of the folly of hypocrisy: “For there is nothing covered that will not be revealed, nor hidden that will not be known. Therefore whatever you have spoken in the dark will be heard in the light, and what you have spoken in the ear in inner rooms will be proclaimed on the housetops” (Luke 12:2-3).
Jesus’ disciples ought to be fearless in proclaiming His word (Matthew 10:27) and eschewing hypocrisy (Luke 12:1) because they do not fear those who can kill the body but cannot kill the soul (Matthew 10:28; Luke 12:4). Rather, they fear the judgment of Him who will bring every work into judgment, every secret thing—whether good or evil (Ecclesiastes 12:14)–and has power to cast into hell (Luke 12:5), destroying both soul and body in Gehenna (Matthew 10:28).
God knows the secrets of your heart (Psalm 44:21). Repenting of your secret sins and then confessing them to God is the only way to properly cover them up (1 John 1:9).