Turn the other cheek

When someone approaches you with force, it's not worth to retaliate - you can't
win the game.
When you're on a spiritual/good-health path, and thus guided by intelligence,
you can't gain the upper hand force-wise as a retaliation (justified defense is
a different scenario).   Intelligence is very powerful, but weak when it comes
to force.   People using force are mind-based and ego-locked.   The mind is very
clever and cunning.   This cunningness enables them to come up with new ideas
on how to trump someone else's cunningness, someone else's force.   And because
they are ego-locked, they can't understand what they are doing, they can't learn
from the reaction of the other(s).
So if you, a spiritual or good-health seeker, get attacked by someone, it's not
worth trying to get even, gain the upper hand, or teach the attacker a lesson.
Your intelligence will not be able to come up with a "suitable" counter-attack.
If you try to use your mind to counter-attack, you strengthen the ego, get
entangled in negative karma, and can fall spiritually.   Thus it's better "to turn
the other cheek" = withdraw from/ignore the attack, when safely possible.
Of course, if the attack jeopardizes your safety (whether physical, emotional,
spiritual, financial, etc.), it's perfectly OK to defend yourself/your Self.
In the case of defending your safety the main differences are in your intent and
in the effect on the attacker.   You are not trying to get even (a negative, unloving
intent); you are defending yourself/your Self from harm (a positive, loving
intent) - in this case your intelligence can guide you towards the best solution,
the best defense.   When you employ justified, intelligence-led defense,
you are not sending the attacker negative energy, as you would in the case
of "getting even" (and thus not getting entangled in negative karma).

Note: examples of someone approaching you with force can be:
- an attempt to provoke you, to insult you, to draw you into a conflict,
    a challenge to fight, etc.