"Do not walk according to the flesh but according to the Spirit." (Rom 8:4)  My buddy Gil McNutt was talking about walking according to the flesh, and he said, "If your sin doesn't bother your conscience, you're walking according to the flesh."

The conscience is a blessing: it can defend us and it can accuse us. If we ignore it and shove it to the back when it's being pricked through conviction about sin,  we effectively start to sear it—and the end of that reaction is that we become liars seared in our own consciences. 

 Is there any sin in your life that you're getting comfy with? Maybe that you're defending a little? That's your warning sign! Reverse your course immediately, get rid of the sin, and be able to say, "I am telling the truth in Christ, I am not lying, my conscience testifies with me in the Holy Spirit!" (Rom 9)