Now if this occurred 1400 years ago as you said, then this marriage occurred when man barely lived to 30 before succumbing to the simplest illnesses. It's therefore much more reasonable to be married to a 9-year old then as opposed to today. Calling him a pervert is a little ignorant by any means.

However, I don't find that's the issue here; the issue is that those with Islamic beliefs use Muhammad's guide as a modern excuse to marry a 9 year old child. Today we live to be 70 years old on average and rising, puberty does not occur until the pre-teen ages, and psychological studies blatantly find that sexual acts with a child before puberty cause drastic long-term consequences to their well-being.

These people use Muhammad's passage as a modern-day excuse to be ignorant and pedophilic, and I believe that's the issue.