The realisation of a unity of being cannot easily be explained, especially if the people you are explaining it to are of a scientific or sceptical mindset.
I could say read the yoga sutras of Patanjali and learn to meditate. I doubt I would have many takers in a place like this.
It is ironic that posters on this forum regard monism as the ontology of favour. While this is not translated into any more substantial appreciation of what one thing existing might entail. They generally stop at the extent of the reach of science at this time. Philosophy can take them a little further, but there is precious little of that here either.