No natural man knows anything about carnality. The flesh lusting against the Spirit that came in at regeneration, and the Spirit lusting against the flesh, produces carnality. "Walk in the Spirit," says Paul, "and ye shall not fulfil the lusts of the flesh"; and carnality will disappear.
Are you contentious, easily troubled about trifles? "Oh, but no one who is a Christian ever is!" Paul says they are, he connects these things with carnality. Is there a truth in the Bible that instantly awakens petulance in you? That is a proof that you are yet carnal. If sanctification is being worked out, there is no trace of that spirit left.
If the Spirit of God detects anything in you that is wrong, He does not ask you to put it right; He asks you to accept the light, and He will put it right. A child of the light confesses instantly and stands bared before God; a child of the darkness says – "Oh, I can explain that away." When once the light breaks and the conviction of wrong comes, be a child of the light, and confess, and God will deal with what is wrong; if you vindicate yourself, you prove yourself to be a child of the darkness.
What is the proof that carnality has gone? Never deceive yourself; when carnality is gone it is the most real thing imaginable. God will see that you have any number of opportunities to prove to yourself the marvel of His grace. The practical test is the only proof. "Why," you say, "if this had happened before, there would have been the spirit of resentment!" You will never cease to be the most amazed person on earth at what God has done for you on the inside.