This excerpt is from Chapter 7, Investing.
 
Why Should You Invest?
 
You should invest because doing so allows you to achieve one or more of your
financial goals. Whether it is for retirement, your child’s education, buying your
first home, or starting your own business, do it because it is something you need to do. You should never invest just because you see others doing it, and you think that it will help you get “stuff” like them.
 
The attraction of financial wealth is strong. Most of our images of success are
associated with being rich. When you are wealthy and the world knows it, people automatically think of you as being smart, glamorous, or famous. These are all things that stroke the ego and can make you feel good. Given all that we know about financial wealth, who wouldn’t want to be rich? But things are not what they always seem. Financial wealth also breeds some other attributes: envy and greed.
 
The following verses in Psalms 73:2–3 warn us of the folly we face when we
invest just because we are envious of what others have accumulated:
2 But as for me, my feet were almost gone; my steps had well nigh slipped.
3 For I was envious at the foolish, when I saw the prosperity of the wicked
The foolish, as referenced here are those who do not fear God. These tend to
be people who are very full of themselves. Oftentimes they are successful and
proud of the many things that they have achieved, and the many possessions
they have obtained. They attribute all that they have to their hard work and luck.
They are wise in the ways of the world, but are spiritually foolish because they
do not recognize God’s grace and mercy. Unfortunately, we sometimes see the
many things that they have contrasted with the many things we don’t have, and
envy begins to set in.
 
You’re living right. You’re doing all that God has commanded you to do. But it
seems that others that aren’t quite as “righteous” as you are enjoying a life of
prosperity. The temptation is that if the wicked are investing and appear to be
prosperous, then maybe you should try it too. Don’t be fooled. Any investment
program that is not guided by the Word of God ultimately will not be successful.
When you decide to invest, make sure that it is for the right reasons.

 
Greed is also a big factor in not only deciding whether or not to invest, but also in how we invest.