I suppose we could go to the source of moral behavior and see what Scripture says about gambling:
The Bible does not specifically condemn gambling, betting, or the lottery. The Bible does warn us, however, to stay away from the love of money (1 Timothy 6:10; Hebrews 13:5). Scripture also encourages us to stay away from attempts to “get rich quick” (Proverbs 13:11; 23:5; Ecclesiastes 5:10). Gambling most definitely is focused on the love of money and undeniably tempts people with the promise of quick and easy riches.
What is wrong with gambling? Gambling is a difficult issue because if it is done in moderation and only on occasion, it is a waste of money, but it is not necessarily evil. People waste money on all sorts of activities. Gambling is no more or less of a waste of money than seeing a movie (in many cases), eating an unnecessarily expensive meal, or purchasing a worthless item. At the same time, the fact that money is wasted on other things does not justify gambling. Money should not be wasted. Excess money should be saved for future needs or given to the Lord's work, not gambled away.
While the Bible does not explicitly mention gambling, it does mention events of “luck” or “chance.” As an example, casting lots is used in Leviticus to choose between the sacrificial goat and the scapegoat. Joshua cast lots to determine the allotment of land to the various tribes. Nehemiah cast lots to determine who would live inside the walls of Jerusalem. The apostles cast lots to determine the replacement for Judas. Proverbs 16:33 says, “The lot is cast in the lap, but its every decision is from the Lord.”
What would the Bible say about casinos and lotteries? Casinos use all sorts of marketing schemes to entice gamblers to risk as much money as possible. They often offer inexpensive or even free alcohol, which encourages drunkenness, and thereby a decreased ability to make wise decisions. Everything in a casino is perfectly rigged for taking money in large sums and giving nothing in return, except for fleeting and empty pleasures. Lotteries attempt to portray themselves as a way to fund education and/or social programs. However, studies show that lottery participants are usually those who can least afford to be spending money on lottery tickets. The allure of “getting rich quick” is too great a temptation to resist for those who are desperate. The chances of winning are infinitesimal, which results in many peoples’ lives being ruined.
Can lotto/lottery proceeds please God? Many people claim to be playing the lottery or gambling so that they can give the money to the church or to some other good cause. While this may be a good motive, reality is that few use gambling winnings for godly purposes. Studies show that the vast majority of lottery winners are in an even worse financial situation a few years after winning a jackpot than they were before. Few, if any, truly give the money to a good cause. Further, God does not need our money to fund His mission in the world. Proverbs 13:11 says, “Dishonest money dwindles away, but he who gathers money little by little makes it grow.” God is sovereign and will provide for the needs of the church through honest means.
Would God be honored by receiving donated drug money or money stolen in a bank robbery? Of course not. Neither does God need or want money that was “stolen” from the poor in the temptation for riches.
First Timothy 6:10 tells us, “For the love of money is a root of all kinds of evil. Some people, eager for money, have wandered from the faith and pierced themselves with many griefs.” Hebrews 13:5 declares, “Keep your lives free from the love of money and be content with what you have, because God has said, ‘Never will I leave you; never will I forsake you.’” Matthew 6:24 proclaims, “No one can serve two masters. Either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve both God and Money.”
http://www.gotquestions.org/gambling-sin.html