I don't think he's referring to the fruit of knowledge of good and evil, I think he's referring to the doctrine of original sin itself, which he's suggesting caused harm by occupying space in Christian brains.
Although belief in the inherent brokenness of humanity is a poisonous meme that can, at its worst, make you hate yourself and mess with the happiness of others, I see it as different from a basilisk. You can still function and lead a goal-driven life while under the influence of religious dogma. It does not paralyze you with terror the way a basilisk is reputed to do.
WARNING: Memetic hazard.
http://www.slate.com/articles/technology/bitwise/2014/07/roko_s_basilisk_the_most_terrifying_thought_experiment_of_all_time.html?wpisrc=obnetwork
Is there anything we should do?