Fortunately, nobody is born an evil person. Or hardly anyone as some would put it. In fact, it's created. It can be created by a broken childhood, a heavy grudge and unappeasable fear. These can lead to a desire for power and money, which you'll have to be a masterful manipulator to do. It might feel good, but eventually it will no longer be worth the suffering you were forced to endure or the inequities you had to face.
For a worst-case scenario, say your spouse was unfairly sentenced to life in prison through the machinations of a corrupt prosecutor. When you find out that the prosecutor himself plotted the whole thing, you can decide to confront him in hatred or vigilantly collect every piece of evidence to undo the injustice that's been wrought. You may need some patience for that to get the conviction overturned, but there's a low probability anybody's gonna have an infinite amount of patience. Even if you do, it wouldn't be a good trait to have because as Edmund Burke said: The only thing necessary for the triumph of evil is for good men to do nothing.
Patience isn't always enough to destroy any evil that lurks within. Sometimes force is needed to overcome what obstacles stand in our way.