In the Protestant Christian world, active repentance, which is examining ourselves, recognizing and admitting to our sins, praying to the Lord, and starting a new life, is extremely difficult to practice, for a number of reasons that will be covered later. Therefore here is an easier kind of repentance: When we are considering doing something evil and are forming an intention to do it, we say to ourselves, “I am thinking about this and I am intending to do it, but because it is a sin, I am not going to do it.” This counteracts the enticement that hell is injecting into us and keeps it from making further inroads.
It is amazing but true that it is easy for any of us to rebuke someone else who is intending to do something evil and say, “Don’t do that—that’s a sin!” And yet it is difficult for us to say the same thing to ourselves. The reason is that saying it to ourselves requires a movement of the will, but saying it to someone else requires only a low level of thought based on things we have heard.
from Regeneration, Page 36