Longman Dictionary of Contemporary English - religion

~ n 1 a belief in the life of the spirit and usually in one or more gods  (The theme was the relationship between religion and literature. | get religion informal (=suddenly become interested in religion in a way that seems strange to other people))  (He got religion in a big way when he was at college.) 2 a particular system of this belief and all the ways of expressing your love for your god, ceremonies, and duties that are connected with it  (Islam and Buddhism are two of the great religions of the world. | the Christian religion | practise a religion (=take part in the ceremonies and obey the rules of a religion)) 3 an activity or area of interest which is extremely or unreasonably important in your life  (Football was a religion in my family.)