Body language is how you communicate with your body. It makes up 55% of your communication which is the majority of it. Voice tone accounts for 38% and the spoken words only 7%. According to scientific research.
Your body language and emotions are linked together. If your feeling nervous your body will communicate it by give off that vibe or if your feeling confident you will give off that vibe. The inverse is also true if you change your body language to someone who is confident you will feel more confident. Another thing about body language is you cannot fake it as it is largely controlled by your subconcious mind. small micro gestures can give away what your truly feeling.
Before humans could speak we used body language and voice tone to communicate, spoken words are only add-ons. A general rule is that woman are more perceptive of body language because they had to raise the children while the men hunted, so they needed to know how there babys were feeling.
In conclusion body language is very important as it is our main form of communication. You CANNOT turn it off as your are constantly communicating something with your body.
GF: (sees lipstick on BF shirt)Were you cheatin on me!?
Bf: NO!(looks left to right nervously)
Try saying "I love you" to someone with a im going to stalk
you look and clenched fist. Your body language will not be congruent with your words.