Om, therefore, represents both the unmanifest (nirguna) and manifest (saguna) aspects of God. That is why it is called pranava, to mean that it pervades life and runs through our prana or breath.

By the 400s, haloes had been embedded in Christian art in Rome and Buddhist art in China. Somehow, in a matter of a few centuries, they had become Eurasia's universal religious symbol of divinity.