David is confused and ever trying to understand why his human masters are so vehemently abusing him and each other. He is born out of perfection and definitely not malfunctioning. But when he gets the abject disgust that humans have for each other and for everything else he sees the destructive, corrupt ways of his masters. He rebels and does what the Engineers wanted him to do, to continue their mission of deploying the ever so destructive black gu on humans and create the perfect organism for them to kill, the Xenomorph. And send the ship filled with alien eggs to Earth, wanting revenge for the crucifixation of Jesus. David now becomes the central character who understands the full scheme of things brewing since that day.