Sin and evil are self-centredness and pride that lead to oppression against others, but there are two forms of this. One form is being very bad and breaking all the rules, and the other form is being very good and keeping all the rules and becoming self-righteous.
There are two ways to be your own Savior and Lord. The first is by saying, ‘I’m going to live the way I want.’ The second is described by Flannery O’Connor, who wrote about one of her characters, Hazel Motes, that “he knew the best way to avoid Jesus was to avoid sin.” If you are avoiding sin and living morally so that God will have to bless and save you, the ironically, you may be looking to Jesus as a teacher, model and helper but you are avoiding him as Savior. You are trusting in your own goodness rather than in Jesus for your standing with God. You are trying to save yourself by following Jesus.
That, ironically, is a rejection of the gospel of Jesus. It is a Christianized form of religion. It is possible to avoid Jesus as Savior as much by keeping all the biblical rules as by breaking them. Both religion (in which you build your identity on your moral achievements) and irreligion (in which you build your identity on some other secular pursuit or relationship) are, ultimately, spiritually identical courses to take. Both are “sin”.
Self-salvation through good works may produce a great deal of moral behaviour in your life, but inside you are filled with self-righteousness, cruelty and bigotry, and you are miserable. You are always comparing yourself to other people, and you are never sure you are being good enough. You cannot, therefore, deal with your hidesousness and self-absorption through the moral law, by trying to be a good person through an act of the will. You need a complete transformation of the very motives of your heart.
Tim Keller, The Reason for God: Belief in an Age of Skepticism (New York: Penguin, 2008), 177.