If it’s all a fiction spun by disappointed disciples, if it’s a mere symbol for the idea of an inner awakening, if it’s not a fact that Christ has been raised, then our grief and loss have no end, and we have no hope.
I think the problem with the idea of eternity is that we do not have any direct experience of it, but we encounter enough of its possibility to be unsettling.
While the world is full of horizons and endpoints, for Christians, there is always tomorrow, and there are people in that tomorrow waiting for us as we wait for them.