Congruency when presenting is very important, as it adds to your credibility, your connection and your competence as a speaker.
Congruency when presenting simple means that all aspects of your communication, your message and what you are saying, line up. Your body language, gestures and nonverbal communication line up with what you are saying. Your passion and your energy are appropriate and line up with what you are saying. Your values, beliefs and your behaviours line up with what you are saying. You literally walk the talk and talk the walk.
This is the only way to present, with absolute congruency and authenticity. Every aspect of your communication must line up.