I look at gambling as an opportunity to win money. Investing in real estate is all together different. For example, if I were to invest in real estate, no matter if the value of the property goes up or down, it is still valuable. With gambling, it is not based on investing, it is based purely on the luck of the draw. For everyone that wins, a lot of people must loose. Also, gambling can become extremely addictive (hey, why do u think u have hotels spending over 1 billion dollars to impress you to gamble in cities like Vegas). For example, my dad use to play about 3 dollars in the lottery everyday since I was born (not including those little scratch tickets and trips to Vegas slots). I'm 22, so my dad since I was born has played at least 24,000 in the local lottery. At most in total he has won about 1,000. So he in essence has wasted 23,000 of his money. If he had put that money into a Roth IRA, by the time I retired, I would be a millionare (that is investing).
In Matthew 25:14-30, discusses the parable of the talent, and in this parable the servant was scolded for wasting the master's money. He didn't gamble it, but he did nothing with it (i.e. too afraid to use it). The master commented on how he could have at least left his money with the bankers so that it could gain interest (hmm..this shows that investing in things like stock market, CDs, IRAs, etc. were considered worthy investments). So if Jesus mentioned this parable in teaching us to be good stewards with our resources, and the very least we could do is have a savings account, then how does gambling relate here? Sure if you are investing in the stock market, you have a chance of losing some money, but I guarantee you that chance is WAY WAY WAY less than gambling. Also, if you lose in the market, you at least have something to work with. In gambling, once that money is gone, its gone. You don't have a stock, bond, nothing to show for it.