I think the philosophers just complicate morality, when it is in fact a simple concept. It is the simple sense of doing what is right rather than what is wrong. It operates on a basic level like our instincts. And if we act against those instincts, we are troubled by our conscience and guilt, similar to how you regret entering that dark alley and not following your instinct to stay close to the well-lit wide road. Yet, if nothing happens, we blame ourselves for our irrational fears, and our learning overwrites on our instincts. Similar to what happens with morality.

Everyone begins with a conscience, but whether to suppress it or to satisfy it depends on the individual. One can go against morality and continue defying it, or follow its rules and maintain a clear conscience. Both have their own advantages and disadvantages, and thus no human being is a clear shade of white or black, but choose a color of lighter or darker grey according to their inclination and as to what they see as right.

So then how can morality threaten life? It threatens life through its greatest weapon: a person's guilt. For a person can destroy, avoid, or deal with anyone, but not their own mind, except by destroying, avoiding or dealing with themselves. Why do criminals give themselves up to the police, even though they could have remain hidden? Its because of their guilt. Nowhere can they escape from themselves and their conscience, and thus they serve their terms in order to appease the conscience and reduce their guilt.

But its possible to destroy the conscience too. Like iron, guilt rusts with time as well. Dipping into the water of crime or immorality several times speeds up the process too. Thieves who make a living from crime don't hesitate before any heist, because poverty forced them into the profession, and the morality rusted and melted away when the results of that action for the individual went contrary to the expectations of their innate principles.

Morality must have been a way to help establish society and civilization, for its based on the basic principle of not harming others when others don't harm you. Going against morality often meant harm to the individual as well, whether by the law or by a retaliation from the victims. However, when that retaliation doesn't occur, the rational mind concurs that the moral limitation is purposeless, and the individual should continue with their illegal/immoral activities. For example, businesses around the world engage in tax avoidance (using legal loopholes to reduce tax paid), because the rewards are significant and there is no legal harm the firm can face. Therefore, what moral obligations the firm has, are easily ignored.

What follows is that morality is constantly evolving along with society. As the extent of harm associated with immoral actions reduces or increases, the moral graveness of the action changes inversely. For example, pick-pocketing could be considered lesser immoral than burglary, partly because it is easier to pickpocket than to steal from a house, and partly because there is a lighter sentence for pick-pocketing and lesser chances to get caught. 

Perhaps I should say that it is better to follow morality than to defy it. Perhaps I should say that an immoral person not only harms themselves, but also others. But then, who am I to judge? Isn't life the pursuit of happiness, and if morality becomes an obstacle in that pursuit, then shouldn't we dispose of it as well? Its may not be good to be a mercenary assassin, but then its not great to be a docile instrument of society (office worker) either. For good to win, there must always be evil to defeat as well. And so, you too must do what we all do unconsciously, is to decide how much of morals and goodness you want to keep, and how much of it do you want to destroy and dispose with. All I can say is don't aim for a pure good or evil outlook; guilt, conscience or society itself would kill such an evil person, and being purely good would be impossible, too suffocating, and even extremely boring.