How
does
Effort to Avoid Protect against Evil?
The Blessed Buddha once said:
There are these 4 best efforts, Bhikkhus and friends:
1: The effort to
avoid and thus prevent all evil states not yet arisen.
2: The effort to
overcome all wrong states that already has arisen.
3: The effort to develop
all the good mental states that not yet has arisen.
4: The effort to
maintain any advantageous state, that already has arisen.
What, Bhikkhus and friends, is the effort to
avoid?
When experiencing a form with the eye, or a sound with the ear, or a smell
with the nose, or a taste with the tongue, or a touch with the body, or a
thought with the mind, then the Bhikkhu neither fixes his attention on the
whole
appearance, nor on any of the object's specific tantalizing details.
He tries hard instead to dispel all the evil and disadvantageous states,
such as greed, lust & longing, that would arise if he left his senses unguarded.
He thus watches over his senses, controls his senses, and restrains his senses.
This is called the
effort to avoid and thereby prevent all evil mental states!

More on the Avoiding Effort!
http://What-Buddha-Said.net/drops/III/Avoiding_Effort.htm


Source (edited extract):
The Numerical Sayings of the Buddha.
Anguttara Nikāya AN 4:14
http://What-Buddha-Said.net/Canon/Sutta/AN/Index.Numerical.htm
Avoid all internal Evil!