After seeing girls get weak in the knees over Robin's man, Gael, who's from Argentina, Barney and Ted decide to pose as out-of-towners, in order to meet chicks.
A religion is a belief system with rituals. The missionary kopimistsamfundet is a religious group centered in Sweden who believe that copying and the sharing of information is the best and most beautiful that is. To have your information copied is a token of appreciation, that someone think you have done something good.