I wonder whether we can compare these two incredible texts by talking about the way in which both texts show that moral neutrality is impossible. This is perhaps most clearly shown in "The Guest," where Daru, above all, tries to do everything he can to avoid taking sides in the conflict that is occurring around him. This is why he tries to let his Arab prisoner escape and then finally gives him the choice of which road to take. Daru's desire is to above all prevent having to nail his flag to the mast, or declare where his allegiance lies. In the end, the Arab's choice to go to prison alienates Daru from the Arabs, as they believe that he has sided with the French in the conflict that has hurt them so greviously. Moral neutrality for Daru, no matter how much he wants and desires it, is something that is impossible for him to attain.
In the same way, in the Grand Inquisitor story from Dostoyevsky's novel, the figure of Jesus is presented as being in some ways rather naive. He returns and begins to perform miracles, completely unaware of the political ramifications of what he does and how his actions will be interpreted. The Inquisitor has to explain to Jesus why the church no longer needs him and how, in the world of power and politics, his seemingly innocent actions are actually incredibly dangerous and subversive in the way that they challenge the status quo.
Both texts therefore seem to show that the world around us and the context in which we find ourselves means that our actions are often forced or misinterpreted. There is no such thing as remaining neutral or innocent in our corrupt world.