Why is there suffering? Not what causes it, but why is the universe constituted in such a way that these causes manifest? Why do we live in a universe in which our Buddha natures are concealed?
If we all have Buddha nature and enlightenment is available to anyone, why have so few people achieved it?
If samsara has existed for infinite time and enlightenment is available to all sentient beings, why are not all sentient beings already enlightened?