What is the meaning of "I know of no greater sin than to oppress the innocent in the name of God" by Gandhi? Give one example in the world...

I am not sure when Gandhi wrote or said the words
attributed to him in the question. Or to which aspect of "oppression of the innocent" he
was referring to.

However, it is quite true that people do
sometime oppress the innocent for personal benefit, but justify their action by claiming
it to actions taken as per will of the god. One of the most glaring example of
oppression of the Innocent is provided by the inquisition in Europe. This practice led
to major injustice like burning of Saint Joan at the
stakes.

I believe what Gandhi must have meant was that to
oppress the innocent is bad enough, but to justify it in the name of God makes it much
worse. It compounds a social crime by making it a religious sin
also.

The biggest example of oppression of the innocent in
the name of god is provided by the action of many religious fanatics that kill innocent
people in terrorist attacks.