Human nature has a blind spot to its own faults and shortcomings. This mirror distorts what is seen in oneself but appears clear when observing the faults of others. Jesus admonishes against judging without first removing the plank from one's own eye in order to see clearly. The apostle Paul warns against hypocritical condemning of others while tolerating sin in oneself. Concealed hypocritical sins within those who have made a covenant with God produce a more noxious stench than the sins of open enemies. The things that annoy or anger about other people's behaviors serve as warning indicators of what God finds offensive in oneself. When spiritual faults appear in others they should convert into mirrors for examining one's own spiritual progress and looking for similar things that grieve God's Holy Spirit. God often uses negative behaviors in people to reflect the hideousness of sins in oneself.

Self-righteous people are blind to their own weaknesses and therefore critical and unforgiving. They have difficulty putting themselves in another person's shoes because they trust in themselves that they are righteous and despise others. A person with an exalted opinion of himself never considers himself guilty of offending someone else. Self-exalting people hold such a high opinion of themselves that they are ignorant of the need to grant forgiveness especially to those they judge as beneath them. This blindness prevents them from seeking God's forgiveness or extending mercy to others.

Human nature lies to a person and deceives him into thinking he is something he is not. Lying to oneself still breaks the ninth commandment. Natural conscience is often silenced by a pretense and a show. A man is naturally apt to make his own corrupt judgment the standard of good and evil. He frames grace according to his own affections and makes a god according to his passion. David's passion drew him away from God. David became blinded by his passion and could not see himself. Even after hearing a vivid story that made him furious David still could not see his fault until told directly that he was the man. David had lost sight of God and sinned against Him. Job somehow thought he could interact with God as an equal. Job could not see the vast difference between the awesome powerful eternal God and puny weak transitory man. When questioned by God Job was crushed that he had been so blind to the obvious greatness of God and His authority over His creation. Peter realized he was a sinful man after witnessing a great catch of fish that occurred at the word of Jesus Christ. Peter saw himself for what he was in contrast to his Creator. All three of these men had their eyes opened so that they could see themselves in relation to God. Self-examination is a necessary commanded duty requiring diligence and brutal honesty. Because of human nature this task is often difficult.