So what?
Seriously: so what if they "deny that it is a sin"?
That affects you directly in what way?
I don't believe there was a literal Adam or a literal Eve or a literal Garden of Eden.
Why should that affect you in any way, whatsoever?
If people said, "All right, homosexuality IS a sin" -- exactly how would that improve your life one iota?
By allowing you to be "right"?
Well, so what if you're "right"?
And so what if people don't agree with you.
I'd like to know exactly how people like you, floatingaxe, IAmRedeemed, DMagoh, etc. are affected directly if someone doesn't think homosexuality is a sin -- or if they have a statue of the Blessed Virgin on their home altar, or they believe that bread and wine become the Body and Blood of Christ, or they don't believe in a literal Garden of Eden.
How is what someone believes -- or doesn't believe -- going to change your life even one iota, and why should that even bother you?