Wikisimpsons - The Simpsons Wiki
Maude Flanders was a devout Christian who once attended a Bible camp to learn how to be more judgmental. She campaigned strongly against Itchy and Scratchy with Marge. She is often partnered with Helen Lovejoy as they protest against the "evils" in Springfield. Maude died after she was knocked off a grandstand at the Springfield Speedway.
Maude was a busy homemaker and a devoted wife and mother. She was also a tireless advocate for children in general, whose innocence, she felt, was often sullied by the "evils" of cartoon violence, liberal education and the insidious influences of popular culture.
Maude and Ned attended the weekend marriage counseling retreat, as they were working on fine-tuning some issues in their marriage. The main one, according to Ned, was that sometimes Maude would underline passages in Ned's Bible when she couldn't find her own.
Even though she spent much of her free time in prayer and reading the Bible, Maude was known to let her hair (and her neckline) down for the occasional dinner party at the home of her neighbors, the Simpsons. Homer has repeatedly demonstrated his lust for Maude.
Maude died after being knocked off a grandstand by a shirt cannon at the Springfield Speedway. According to Homer, he had parked in the ambulance zone, preventing any quick resuscitation. Her death crushed Ned Flanders (as well as Todd and Rod Flanders), who, though used to some measure of hardship (their house getting destroyed  and car crashes among them), assumed that they would always be together.
Apparently, Homer fell in her grave, which Ned mentioned.
Reverend Lovejoy eulogized her as follows: "In many ways, Maude Flanders was a supporting character in our lives. She didn't grab our attention with memorable catchphrases, or comical accents. But, whether you noticed her or not, Maude was always there ... and we thought she always would be." 
After Maude's death, the grieving Ned saw in her sketchbook a series of drawings that outlined a plan for a Christian-themed amusement park named "Praiseland." Realizing this park to be her final dream, Ned acquired the defunct amusement park "Storytime Village" from Colonel Antoine "Tex" O'Hara ("The Rich Texan") and, with the assistance of Homer and other townspeople, built and opened Praiseland. He memorialized Maude there with a statue of her, and placed on its base a plaque bearing the phrase "She taught us the joy of shame and the shame of joy." Praiseland sold Maude memorial items such as masks. Praiseland gained popularity among the residents of Springfield when they erroneously attributed to the statue of Maude the performance of miracles providing religious experiences. The religious experiences were actually hallucinations, caused by gas that was leaking from a gas line near the base of the statue. Feeling that profiting off the memory of his dead wife was wrong, and even more so after candles near the gas leak nearly caused an explosion, Ned closed down Praiseland.
 Post-mortem appearances