Pick over kidney beans, place into a large bowl, and pour in enough water to cover by several inches. Soak kidney beans overnight.
Drain kidney beans, transfer to a large soup pot, and cover with 3 quarts fresh water.
Stir in green bell pepper, onion, celery, salt, black pepper, Creole seasoning, and garlic.
Cover the pot, place over medium heat, and bring to a boil.
Reduce heat to low and simmer until beans are tender, about 4 hours.
Mix smoked sausage into the beans; cook an additional 45 minutes, stirring occasionally.
About 30 minutes before serving time, place 2 cups water and margarine into a saucepan and bring to a boil.
Stir in rice, return to a boil, and reduce heat to medium-low. Cover the pan and simmer until rice is tender and liquid has been absorbed, 20 to 25 minutes. Remove from heat and allow to stand covered for 5 minutes.
