While hinted at in nearly every chapter, lesson 8 focuses the student's attention on the sin of covetousness. The purpose of lesson 8 is "to impress upon the mind that covetousness is one of the most deceptive sins known to man" (45). That word "deceptive" plays a key role in this lesson. The lesson is entitled "A Spiritual Cancer." When one studies this lesson, he/she can see why "cancer" is used.
The lesson opens with some examples of covetousness in the Bible (Achan, Gehazi, etc.) and what other sins that one sin led to. As brother Black points out, "Few sins are so distinctly and solemnly denounced in the scriptures as covetousness" (45). He then goes on to list several verses from both the Old and New Testaments that teach against this dangerous sin.
On page 46, brother Black takes a few moments to remind us that money is not wrong, but the "love of money" leads to all sorts of sins (First Timothy 6:10). Because we love money, its power eats away at us, causing us to do things we would never have envisioned ourselves doing.
After sections building on the main points of the introduction, brother Black has an interesting section that should cause every student to think (pages 48-49). He speaks of covetousness as the only sin that he had never heard anyone confess. While it may be one of the most committed sins, no one seems to want to admit his/her error in this regard.
In the brief final section (page 49), brother Black reminds us that covetousness is listed with other "terrible" sins, such as adultery and extortion. That alone should cause us all to think seriously about how important God thinks this subject is.