There is a likely neural basis for religious experiences which accounts for many if not all such experiences.

From studying epileptic patients who suffer seizures of the brain's frontal lobe, scientists found that patients frequently experienced mystical episodes and often become obsessed with religious spirituality.

The feeling of God's presence that she's there with you, that your prayer is being listen to, the comfort of love, seeing the light. This supposed religious experience has been induced by scientists stimulating the frontal lobe in 80% of subjects including atheists.

Interesting Heh. 

BTW, alternatively alien abductions sensation and demonic posession can also occur by the stimulation of the frontal lobe.