Ethical egoism is the doctrine that you should do only what is best for you and that helping others is only a good idea if you get a good feeling or some other comeback from it. It’s biggest and essential flaw is this: “If you come first or alone matter then it follows you must tell others to serve others not themselves. You tell them that so that you will benefit. Ethics is that you which you have to tell people to do for it ethics is essentially about principles. So ethical egoism contradicts itself for you cannot teach it to others.”
By the way if it is principle that I come first or alone truly matter then I am declaring myself divine! Others are just my subjects without knowing it. The idea that ethical egoism is religious in its own way is irrefutible. That means religious people may indeed be religious but not in the way they want you to think. The Catholic saint and the ascetical Hindu monk are not really Catholic or Hindu religionists - it only looks that way.
It may be that people who preach altruism are in fact egoists! They are very manipulative if that is the case.
Many say that ethical egoism is not ethics! They would say, "There is something wrong with an ethics that tells you to take from others for only you matter to you. Ethics cannot be just about you. And if it has you pretending like our manipulative "friends" it is incoherent for a manipulation based ethic is as logical as a poison laden health drink."

If you disagree then what about ethical egoism in relation to God?  It is a contradiction to say it is ethical to take from God and give yourself the love and respect that he your creator deserves.  Ethical egoism is not ethical at all when you are the subject and God is the object.