What does heresy of rain mean in The Scarlet Ibis?

I believe that it means that rain is generally a good thing, an essence of life. The crops are withered from the drought and rain is needed to restorelife to the dying cotton plants. When it finally comes, instead of giving relief, it splashes on the body of the limp, dead Doodle. Contrary to orthodox viewof the restorative power of rain and water, it has no such affect on Doodle, thus the "heresy of rain."