"For not knowing about God's righteousness and seeking to establish their own, they did not subject themselves to the righteousness of God." Romans 10:3
While Satan indeed is to blamed also for why the world is a mess but the one responsible for sin entering into the world was Adam himself. Romans 5:12-14 declare that Adam's sin caused sin to enter into the world. Satan tempted Eve but the blame fell on Adam who was responsible for all creation including his wife. While demons do entice people to sin but the worst enemy of the person is not the demon but themselves. It is because they embrace the demons and sinfulness in their own freedom of choice between good and evil. When Adam and Eve ate the fruit, they did it with their own wrong choices.
The self-righteous spirit also misleads people away from salvation. You have people who do good works that are not wholly good for their own glory. You have people who live so sinfully (and some do have a facade of righteousness which is not authentic righteousness) yet they think nothing is wrong with them. You have homosexuals who say that they are morally upright even if their lifestyles show other sins besides homosexuality. You have religious people who live very sinful lives. Yet, the self-righteous spirit in them tells them, "There is nothing wrong with you. Do not listen to those lunatics who tell you that you are not saved and that you need Jesus. You are fine the way you are." How ironic so many people hardened in sin think they are righteous people.
To attack the self-righteous spirit, one needs to present the Law of God towards the lost sinner. Galatians 3:24 teaches us that the Law is the schoolmaster that leads people to Christ. It is not enough to say, "You are a sinner." without presenting the Law. People need to understand how they have broken the perfect plan of the Law with James 2:10-11 and Romans 3:19. They need to see that they have offended God's holy, righteous Law even at one point. It takes time before any person becomes that good soil hearer as everyone has lack of depth, hardness and thorns to deal with before they can truly become the good soil hearer and get saved.
Forget About The "I Love Me" Theology