The mentally ill do. Police and criminals do. Heterosexuals, homosexuals and bisexuals do. Catholics, Protestants, Jews, Muslims, Hindus, Buddhists, Agnostics, Atheists, and even Mormons do, no matter how devout or spiritual they do or don't appear to be. Computer users do.
Nice people do.
Maybe you do. Many abusers and abuse victims do not realize that they are, in fact, in an abusive situation. Through these lies we distort reality as we perceive it, we redefine the meaning of what we do, and we adjust what we consider to be right and wrong, in an escalating fashion. Ultimately, any act, no matter how hideous, can be carried out once we have developed the necessary level of denial.