Scripture? The GB has spoken!
The reasoning in the article is that sincere people get baptized and God only hears sincere prayers. So only God only hears prayers of baptized people. Illustrated as: "Human kings do not allow just anyone to enter into the royal palace unannounced. An audience with a king is a restricted privilege. So is prayer to the King of eternity."
Ow, my ex went mad when she discovered this. We had tell our Bible studies sort or less that their prayers would not be heard. To me it was an eye opener.