I feel that your opinion has some errors that I'd like to address. First of all, we have not always been saved. Sin entered the world at the Garden of Eden when Adam and Eve ate of the forbidden fruit: "Wherefore, as by one man sin entered into the world, and death by sin; and so death passed...
Original sin is inherited from Adam and Eve--they were the first to sin. This doesn't literally mean we have physically gotten it in a gene; everyone has been born into sin because of the sin of Adam and Eve. When we are born, we are not perfect human beings; we have a sinful nature. Sin is not...