If a metal helmet can't keep bad thoughts out in real life, what can we use instead?
Just because something sounds nice, doesn't mean it is from the source of good.
Scriptwriters continue to come up with new ways to help the heroes win, even when the odds are against them. God is far more creative and capable than even the most talented writer, though.
If it's easier to travel on a straight path, why do we have such a difficult time of it?
The path to life is narrow, and Jesus is the only way. However, upon accepting Him, we have great freedom and liberty to love and to serve both God and others.
As challenging as our individual weaknesses may be against specific temptations, we are not alone in this struggle.
When we are tempted to sin, even by learning what sin is, we can't just drive out bad thoughts. Something else needs to take their place.