rationalskepticism.org

John Platko wrote: So exactly what is the down side then?

As an example certain religions hold homosexuality as a sin and believe the individual has freely chosen that lifestyle.
This can lead to imposing guilt trips, suicide and even murder.

Surely you recognize the benefits of having a more accurate understanding of the how the universe ticks?

John Platko wrote: What other use of the word mistake is there?

Related to the above - you yourself claimed sin is a mistake.
It could be an inaccurate description.

So when a meandering river on a plain forms an oxbow lake is it a mistake? Should the river have taken the more direct path right off the bat?

A mistake (like colour ) is an illusion in the philosophical sense.