I have metaphysical ideas about that, maybe as a counter-reaction to the brutal harshness of many monotheistic religions. The idea is that only I in this reality have consicousness and sentientness and all other beings (including people, of course) in fact do not feel, do not have consciousness and sentientness, so de facto do not exist.
For my mind endless damnation of even one being is absolute nonsense, I would definitely prefer everyone to be happy and comfortable without end. I struggle profoundly with religious questions and beliefs. I "can't" do examination of conscience and confession because it is very complicated, it appears to require good executive functions, I have problems with defining what is a sin in fact and how serious any sin is.
But monotheism is completely rational to me.