I found this couplet from Omar Khayyam particularly beautiful and in line with mysticism in nearly all the world’s religions. To create a better world, and find a new spirituality for us, this is a better pursuit rather as opposed to fighting on theology, which is always open to interpretation.
I sent my Soul through the Invisible,
Some letter of that After-life to spell:
And by and by my Soul return’d to me,
And answer’d “I Myself am Heav’n and Hell :”