The author does not emphasize a significant reason why this is. In Russian Orthodox belief, there is no purgatory. This is one of the key reasons they consider the catholic heretical. In their belief system, the suffering, that’s supposed to clean us of our sin, happens while we live and not afterwards. Suffering in itself is good for the soul. This is why there’s a saying in Russian about violent husbands: “beats, that means he loves”. Not beating my wife was considered amazingly progressive by my Russian relatives 20 years ago. And this is also why they don’t care about their fallen soldiers or treat GULAG sites like the sites of former concentration camps. Suffering is good for you.