Retard- verb- to slow down, delay, or hold back progress, development, or accomplishment. -noun- a mentally handicapped person.
One need only look at the current state of stem cell research to know that religious zealotry has hindered progress. I could go on with more anecdotal evidence but I don’t want to write a novel.
As for their supposed mental handicap... well I knew that jesus and his priests were con men and charlatans when I was nine years old. Nine. Which makes me question the mental abilities of anyone who still claims supernatural beliefs.
And yes, describing the religious as retards is purposely derogatory, and incendiary. I don't care. They deserve it.