The true battles in life are not physical battles but from the mind.
For just as Christ stated the sins always starts within the mind first.
For first  you think first some sin into realization, then you act on it.
But before the realization, you can kick that sin to the curb.
Thus not acting on the sin either for example lust begins in the mind.
You see a person that turns you on , then your thoughts become carnal.
Then you try to meet the person to act out that sin that grips your mind.
Thus becoming a full fledge  sin that you purposely start acting out on.