The only means we have to free ourselves from habitual self-deception is the mirror of the Word of God.
Scripture never condemns anger per se. As a matter of fact we are given examples of appropriate, godly anger in the life of Jesus and a number of His followers, and we are actually commanded to “be angry” at times (Eph 4:26a). Obviously if God is angry at sin it cannot be wrong for believers to be angry at the same sins. Righteous anger reacts against actual sin, not against inconvenience or violation of personal preference. Righteous anger, instead, is concerned about the Lord and His glory. It is focused on what offends God and injures others, not about what harms the angry person. Righteous anger is self-controlled and concerned for the good of others.
“The power of the human mind to deceive itself seems infinite”1 The Greek philosopher Demosthenes said, “Nothing is easier than self-deceit. For what each man wishes, that he also believes to be truth.”2 In his confessions Augustine wrote, “Man’s love of truth is such that when he loves something which is not the truth, he pretends to himself that what he loves is the truth, and because he hates to be proved wrong, he will not allow himself to be convinced that he is deceiving himself. So he hates the real truth for the sake of what he takes to his heart in its place.”3
The fact that we are easily self-deceived should surprise no Christian for, as the inspired prophet Jeremiah wrote centuries ago, “The heart is more deceitful than all else and is desperately sick, who can understand it” (Jer 17:9)? Jeremiah quickly adds, I, the Lord, search the heart and I test the mind, even to give to each man according to his ways, according to the results of his deeds.” (v.10). However, this deceitful heart, which each of us inherits as a result of the fall, leaves us in a bit of a quandary. How are we supposed to function so as to walk authentically before the Lord? If even the best and most sincere can be deceived by their own hearts, then how can we have confidence that any of our actions, thoughts or motives are pure? How can we be sure that we are not deluding ourselves no matter how hard we try to live in integrity?