Children and teens model the behavior that they observe. The more consistent we are in what we do and in what we say, then the more positive behavior we will observe in the children and teens around us.
There is a high price to pay when adults are inconsistent. Remember all the problems David had with Absalom because of David’s lofty words and grievous sins.
The research points to three consequences of inconsistency. First, the effects of your teaching are diminished when deeds and words are not in line. The more inconsistent you are, the more you will hear yourself saying, "How many times have I told you not to do that?" Second, children can readily recognize inconsistencies, and they become more upset with their inconsistent parents than children who have parents who are more consistent.
Third, a parent who does one thing but expects or demands the opposite from a child is more likely to have discipline problems and more likely to punish a lot in the effort to overcome the influence of his or her own modeling.