She of Little Faith

Bart orders a model rocket and Homer builds and tries to launch it.  With help from some nerds and a hamster named Nibbles, a new rocket is built and launched, but results in the church being destroyed.  The church looks to rebuild and Montgomery Burns offers his help, but only if he can run the church like a business.  The over commercialization of the rebuilt church puts Lisa off; she leaves it for good in search of a new place to worship.  She finds Lenny, Carl and Richard Gere at a Buddhist temple.  Richard gives her some information about Buddhism and she converts.  The family tries to use Christmas as a means to bring Lisa back to Christianity.  Realizing what they are doing runs to the temple but learns from Richard that Buddhism allows for the tolerance of other beliefs.  So as Homer puts it, she can "pay lip service" to Christianity while remaining a Buddhist.