Step 1: Identify a cause
Step 2: Convince self that cause is bigger than anything else in life, and sometimes life itself (be it themselves or others, especially others.) Irony is when pro-life peeps bomb abortion clinics or murder abortion doctors.
Step 3: Go far and wide and preach the said cause and make that your life.
Step 4: All malicious, violent acts stemming from the said cause are now justified.
What I don't understand is, having a cause should give one purpose not introduce anger, or are the bitter ones with lots of anger more inclined to becoming a fanatic?