In the Bible it is referred to as the Tree of Knowledge of good and evil, not just "Knowledge." Significantly, that parable refers to matters unrelated to people doing harm to one another: "discovering" their "nakedness" as being 'wrong'. So the parable specifically suggests that moralizing in matters pertaining to sexuality that do not involve anyone doing harm to anyone else are as pernicious as that 'original sin' was. Yet, the rest of the Bible (up to the message of Jesus, anyway) is all about moralizing and judgment, including--emphasizing, even--innocent sexual matters.