First, the whole concept of morality is a human made construct. The issue of morality doesn't really exist in nature. Because we are a social species and we have a very large and complex brain we developed a capacity thinking about morality. By definition, if we have the capacity for moral behavior then we also have the capacity to be immoral. You can't really have one without the other. Some humans are born psychopathic, which means the question of moral or immoral doesn't matter to them. But most of us are not psychopaths and we are often challenged by moral dillemmas in this life. The reality is that all of us, no matter how hard we try, will behave in less than moral ways at times. The best we can hope for is that we can try to live a moral life, but understand that each of us will stumble in this effort at times.