One of the moments included to illustrate Sherlock Not Being Good With People involves him telling a bereaved child that people don't go heaven when they die, they're taken to a special room and burned.

And then we have that moment in "Dark Water" which amounts to Moffat telling an audience full of children that people don't go to heaven when they die, they just stick around and helplessly endure being burnt or whatever. (I do sometimes wonder if Moffat understands that Sherlock's not actually a role model.)