Let's look at the different levels of communication and how they influence on each other.
First and most visible level is level of verbal communication. This level is about WHAT we pass through communication process. We think that words and content is the most important of all other communication channels, but its only one of several and only small ammount information goes through it. Even if its easiest way to express yourself, its only top of iceberg.
The next level is para verbal communication - it contains charachteristics of speech and answers the question HOW we say things. Our speed of speech, intonation, volume and etc. and through this level we can pass more than just content, but what is more important - information about how inspired and interested we are in the content, how confident we, what happens to us when we pass message.
Research shows that the non verbal communication transports 98% of all information. At this level we pass information about our emotional condition through gestures, posture, facial expression, our apperance and even smell.
The deepest level of every communication is the level of emotions. Our values, attitude, mood - all this components are hidden here. It seems that they are hidden, but actually we cant hide it - they will appear on the higher levels. Actually, each lower level influences on the higher level.
For, example: you can prepare content and structure of your speach, but if the tone of your voice and intonation dont help you to pass your idea efficiently - the content does not have sense.
Even if you have interesting ideas supprting by para ferbal level - your body language should be appropriate. If not - you will not have the best result of communication.
And I am sure that you had in your life situation when you see person talking with you with a nice words in a good pace supporting message with efficiant gestures - but in the same time your heart does not believe what this speaker says. It happens becouse emotional level influence on all other levels. It uses all other levels do bring itself through different signs like a gates to emotional world.
its important to add that as soon as we can build our communication at different levels (we can speak or we can use only body language) - we can also communicate only at emotional level. We can recieve information and we can pass information about our internal condition even if we dont use words or gestures.