But if you think about it a little more logically...perhaps there is something to Walter's statement.
If you look at physical money, there's no intrinsic value to it. The paper and zinc aren't especially rare (more can be printed daily if needed) and the markings on the bills aren't anything new. The only thing that gives physical money (or even digital money) value is the value that everyone else in society gives it. Money is a completely fake institution...but it's been accepted by everyone as having some sort of intrinsic value. Why is that? What "value" does money temporarily hold?
In short, money (at least in theory) is holding the value of time and work. When you head out to work, you're putting your time and effort into a job, and as a reward, you're given currency which indicates that, yes, this person has worked and put in time. The more work and time you put in, the more money you have. It's what makes money almost noble, for to attempt to acquire much is to work hard and put in long hours. In these cases, you could make the logical case that money...at least for the majority of one's career...is life. It's the receipt of your work, and the ticket to buying all the other things one needs to get through the years.
So what's the danger in money then if money contains an intrinsic value? It's precisely the fact that all money earned was earned with someone's time and effort...so to gain money without working or to pursue money solely for its own sake misses the point. To steal is obviously wrong; you're taking someone's time and effort away. To gamble, then, is a form a stealing. You're taking something (money) that you didn't work for. Yes, everyone else involved was "ok" with you stealing, but it's a form of theft nonetheless. Even attempts to set up a scheme or flimsy business to earn money can be dangerous as you're willingly separating people from the time/effort vouchers they've earned. Money is life...as long as you're earning it the right way.
Of course I'm no economist, and I know that markets and shares and currency is much more complicated than I illustrated here....but still, I think it's interesting to take a step back and look at some of the wisdom stated and suggested in some of these old texts. Though they may seem a bit dated in the modern day, there's a lot to think about there. Think about that the next time someone tells you "money isn't important". It's actually your life...converted into paper and metal.