How do you tell a beginner not to resist techniques?

[Kung Fu Wang]

Why did you punch me in the face ?

Since in sparring, I "only" try to punch on my opponent's head, when my opponent tries to punch me on my body, I always ask him, "Why do you bother to punch on my body for?"

Old saying said, "If you don't punch on your opponent's head, you may have to fight him from sun raise until sun set."

The funnest thing was when I helped my long fist teacher to correct my junior long fist brothers in their form, I always moved their horizontal punch to a 30 degree upward punch. I told my junior long fist brothers that I believe in head punch and I don't believe in body punch.

Body punch:

Head punch:

 

[JP3]

Another part of it is that slow, deliberate movements don't often work as well against resistance. It's a lot easier for my partner to step out of a throw if I'm doing it at 1/2 speed. It's easier for them to regain that structure so they can outmuscle the technique.

It's not actually "another part of it," It is It. When you are moving slowly, the other person's body is unconsciously correcting the entire time. This happens at the cerebellar/spinal cord level, they're not at this point trying to bust up your technique intentionally, but their body & balance control centers are, unconsciously. I'm speaking of people practicing in good faith here.

When you go faster, you Are taking their balance and they don't have the time to react, to correct, to regain posture/structure and/or balance.

I agree with @wab25, getting the kuzushi, the balance-breaking, is everything in an on-contact technique, i.e. touching/grabbing/holding the opponent partner.

 

[wab25]

I told my junior long fist brothers that I believe in head punch and I don't believe in body punch.

Its not really a question of whether you believe in them or not... they are devastating:

 

[Yokozuna514]

My guys tell me you get to throw one face punch.

Well the lesson should be learned after one face punch. Any more than you are being a dick if you are a black belt sparring with a white belt.

 

[Yokozuna514]

Since in sparring, I "only" try to punch on my opponent's head, when my opponent tries to punch me on my body, I always ask him, "Why do you bother to punch on my body for?"

Old saying said, "If you don't punch on your opponent's head, you may have to fight him from sun raise until sun set."

The funnest thing was when I helped my long fist teacher to correct my junior long fist brothers in their form, I always moved their horizontal punch to a 30 degree upward punch. I told my junior long fist brothers that I believe in head punch and I don't believe in body punch.

Body punch:

Head punch:

Taking someone out with body punches takes a high degree of skill especially if you only have 1-/2 to 2 minutes to do it. I'm speaking of competition mainly where participants have to follow a rule set. Once you lift this rule set, the game changes.