“You don’t have to understand to believe” never, ever, ever made coherent sense to me.
Do you believe in both general relativity and QCD? Do you understand the Universe? Until the map is indistinguishable from the territory we will have incoherent beliefs about things that we don’t fully understand. It’s the degree of confidence in our beliefs that matters. GR and QCD are incoherent, but we can have extremely high confidence in our beliefs about practical things using those theories. Black holes and dark energy less so.
Do you believe in both general relativity and QCD? Do you understand the Universe? Until the map is indistinguishable from the territory we will have incoherent beliefs about things that we don’t fully understand. It’s the degree of confidence in our beliefs that matters. GR and QCD are incoherent, but we can have extremely high confidence in our beliefs about practical things using those theories. Black holes and dark energy less so.