Casting a spell, in self-defense or in self-interest is not selfish, but positive, life-affirming. You have been given powers, the very same powers that society devalues... What if it comes back tenfold? Well, don't be a fool. Never use your magick to attack the innocent. Then you have nothing to fear... Don't be frivolous or cowardly. If your course is righteous, and your tools ready, go to it.