Wow. What a question. I have a few observations to make.
First, the question asks “What does the bible say…” I could do a search in a bible concordance and list everywhere the word “selfish” occurs, but that wouldn’t really do much. The fact is that the entire bible speaks to the relationship between ourselves and our creator. The Old Testament makes much of “Chasing after other gods”, but it really does little with the idea of making gods of ourselves. So rather than just dealing with what the bible says, I think it is much wiser to draw from the principles that the bible lays down in order to draw some conclusions about someone who is completely self-absorbed.
Second, we should talk about “the self”. This obsession with the self is a relatively modern phenomenon. For most of human history people thought of themselves, not as individuals but as members of a tribe or at least of an extended family. The greatest curse that could be visited upon someone was that they would be childless. Children meant security. Children were the retirement account; the savings of a couple. That was one of the spectacular things about the calling of Abraham; he was told to leave his territory and move to a place where he was a complete stranger and had no outside support of any kind. In making that move he became completely dependent upon God, since God was the only one he knew in that place. Imagine moving someplace that is full of people just looking to rob you and having everything you own in plain sight for all to see. Even if you are well armed and watchful, you have to sleep sometime.
Nowadays people are much more free to live their own lives and are much more secure. Retirement accounts and pensions and Social Security have provided people security into their old age without having to rely upon their children or other family members. While scammers and other thieves still threaten the livelihoods of some retirees, each of us is much more secure than people have ever been before. As a result, many of us live lives that are much more selfish than our predecessors ever dared to dream of. Back then, if you were prone to speaking your mind the way many people do today, you would find that you had offended the very people who were supposed to take care of you at the end of your life. If you ran off the members of your family, a lonely old age would be physically dangerous. In the past hundred years or so, American society has been structured so that we are free to live lives that are as selfish as any of us wishes to.
Third, we should talk about the ultimate end of people who are habitually selfish. So where does all of this leave us? The sin of Adam and Eve was that they wanted to be like God. They wanted to know like God. They wanted to be independent like God. They wanted to be able to choose for themselves the way God did. In a word, they wanted to be able to be completely selfish without consequences. As they say, human beings are the “Crown of Creation”. We have been given abilities, opportunities, and the freedom to make our own choices, even when they are bad choices. Along with such freedom comes responsibilities, and consequences.
You and I get to choose, each day, what we will do, whom we will obey, and whom we will worship. If we do the things that we wish to, and obey our own impulses and desires, and if we worship at altars erected to ourselves, then we will have made ourselves into gods. So the question is; is that a sin? My response is a question. Is there in reality any other sin? When we have made ourselves into gods and when we follow our own desires then we choose to obey ourselves. They say that sin is nothing other than separation from God. To follow only oneself is to make of oneself a tribe of one, a family of one, a church of one, a life of one and a heaven of one. When we die, where will be our heaven? Our heaven will be without God, and we will spend eternity by ourselves, all by ourselves, worshipping the beauty of The One. Me.
If that’s not a frightening idea to you, you may be in trouble.