The Apostle Paul wrote in 1 Timothy 6:9-10a: "People who want to get rich fall into temptation and a trap and into many foolish and harmful desires that plunge men into ruin and destruction. For the love of money is a root of all kinds of evil."
Stewardship
Christians are responsible before God for how they invest the resources entrusted to them, as the parable of the talents (Matthew 25:14-30) makes clear. In many cases, money spent on gambling is money that should have gone to provide for the well-being of one's family or the advancement of a worthy cause. In all cases, it is an unwise investment with an almost-certain negative return. More importantly, such spending propagates an immoral, predatory and exploitative industry.
See also Genesis 1:26; Romans 14:12; 1 Corinthians 4:2; 2 Corinthians 5:10; Colossians 3:17.