The most common sin in the history of the world, is indifference, or the belief that one does not need instruction in Bible doctrine. And thus sin creates the delusion that you can know God, without obeying God. And that is why people fail.
Sin creates a delusion, and here Paul describes it as a deception.
The commandments written by Moses, describe the perfect set of rules for the perfect life. But as we have already studied, those commandments when confronted by sin, cause an excitement of action within the individual, to pursue sin.
The rules of truth are seen as a barrier or a prevention from pursuing ones innermost desires or lusts, and therefore becomes a confrontation within the sinner in their pursuit of their own imagination, or indulgence of evil passions.
When giving into the delusion, you become deceived in believing that what you are thinking or doing is going to benefit you in some way, but the real result is that your pursuit in the realm of sin, is actually spiritual death.
Indifference prevents learning, and lack of learning prevents understanding, and lack of understanding prevents discernment, and lack of discernment prevents spiritual growth.
One needs spiritual growth in order to be able to see and understand reality in its true light, and thus complete oneself, within oneself.
The delusion of sin, is that you can attain the same result without God or doctrine, or even be better off. And the result of pursuing this delusion, is failure, and loss, which extend into eternity, and therefore become a huge price to pay.