The practice of spirituality directly relates to human brain.
Normal human beings used their brain 1 to 2% the remaining always lying dormant. When we indulged in spirituality the dormant lying portions of our brain start activating!
This happens because way of practicing spirituality is via contemplation (chintan) and chintan uses brain power to its full capacity. So much so that when we are in deep contemplation one often experiences very severe headaches that may sometimes continue for days.
In my search for God from six years of age and in absence of a spiritual master to guide me, I often experienced headaches continuing for days. Not knowing what it was and why it happened, my father took me to the best doctors in town and outside but to no avail.
None in the medical world knew anything about spirituality. How could they even guess that headaches were a result of activation of dormant lying portions of brain!
As our spiritual progress accordingly the activation of brain. An enlightened one like Mahavira, Gautama Buddha even Jesus Christ and Prophet Mohammed after reaching state of enlightenment used their brain 100%.
Full activation of brain 100% means the entire wisdom contained in cosmos is now at our tips. Prime reason why enlightened ones are also called knower of all!