Supermarket Game
This is a great game that you can use to help out your local food bank. The only cost involved is the money that will be used to purchase the groceries. You also will need the permission of your local supermarket. Most supermarkets will be very cooperative if you plan on having the event at a decent hour. You will also need to prepare a list of items that your local food bank is in need of.
Divide the group into teams of around five people depending on how many you have in your group. The object of the game is to buy as many items as you can while staying under the restrictions of the game. The first restriction is money. A team that goes over their limit is automatically out. The second restriction is that they may only buy a certain amount of the same item. For instance, a group can't spend their entire limit of $50 on canned beans. The limit on the individual item depends on the amount of money available and the list of items. You may add as many restrictions as you would like.
You may also want to add some side games. These games act as bonus points for what the team earns while shopping. Examples would be answering various bible trivia questions during the event or assigning a special item that is worth some amount of points. Once the event is over and the winners have been announced, the group can then take the purchased groceries to their local food bank.