Ahmedali111“I didnt say sex is against nature in itself,”
No, actually this is what you said:
"To consider religion a taboo subject but sex as something normal is quite against nature!"
To consider sex as something normal is (quite) against nature (in itself).
I would omit the words in parentheses as they sound a little unnatural and unnecessary to me. However, they add nothing important to the meaning of the sentence. What you said is: to consider sex [as something] normal is against nature.
CB