Every Christian carries within himself a degree of carnality, that is, worldliness, weakness, and vulnerability to temptation. A difference between actual "carnal Christians" (as described in 1st Corinthians 1-2) and mature Christians is that a mature Christian sees his weakness, admits it to himself and God, confesses it when he falls, and consistently applies himself diligently to moving forward. The "carnal Christian" is blind to his weaknesses, or in denial because of pride, won't call his sin "sin", and is lazy about moving forward.