Answer:
As far as I am aware, this is false.
Explanation:
From what I've read about egyptian mythology, Anubis does not have a brother, only a half brother, Horus. What you've heard could be coming from a work such as Rick Riordan's The Kane Chronicles, where Egyptian mythology is adapted into novels, sometimes with various changes or additions (although Rick Riordan does do a pretty good job at keeping things authentic).
Because it allowed the people to trust their leader if they all supported chritianity, because then they could all relate spiritually. Hope this helped :P
What is your question? All you typed is "The English colonists."