"No-one has been able to prove the existence of God," he says, adding, "because there IS no God. God is man's creation. God doesn't exist. It is just a word."

Ravi Kumar grew up in a fairly religious home: his parents and grandfather were devout Hindus who would visit temples and perform rituals on religious festivals.

"My father took me to temples and as a child I went in because I was curious to see what was there."