The most basic reason why this world is not a world of peace, harmony, and mutual respect, really comes down to the fact that far too many people, lie far too often. That is to say, though lying often serves the purpose of deception, the truth of the matter is, that most people avail themselves of lies, not so much for deception purposes, though they do, but typically as a ways and means to take inappropriate shortcuts in life, so that by doing so, they subsequently will not have to face the music of that which they should face for those actions and deeds accomplished through the art of lying. This thus means that by lying they are attempting to divert having appropriate justice be served upon them.
While some will say, that people that lie, will eventually get caught up in their lies, in the scheme of things, life actually teaches us that in this world, lying, for an inordinate amount of people, can actually work out quite well for them. The fact that some of those that lie, seemingly, get away with it, is a contributing factor towards other people, justifying their own lies, so as to hopefully get the same sort of positive result. In other words, as much as we might wish that our justice system both socially as well as in a court of law, would be absolutely perfect and thorough, the reality of the situation is that ultimately in many cases, those that lie, are going to have to be the ones to correct their own behavior, for the proverbial watchtower can only catch so much of mankind's sins, lies, and follies.
To understand better why it is so important within society, that we are honest with one another, it must be recognized that virtually every crime as well as virtually every stupidity that people do, is based upon the action of lying in some way, form, or manner. This signifies that honest people, do not commit crimes, except those crimes of conscience, or of ignorance, and in all cases, have the integrity to own up to what and who they really are. As for those that lie, far too often, the truth from their own lips, never emerges, for liars, typically veer so far off the straight and narrow, that they have absolutely no intention of ever getting back onto the right path, for they are completely unwilling to own up to who and what they are, because they do not desire to ever face the fair consequences of their bad acts.
All of the above means that those that are parents should definitely be concerned about the lies that their children tell them, and should not dismiss even little lies, that have little consequence, of being of no real concern, for those that first get away with a little lie, are often those that are emboldened to pursue yet a bigger and then a bigger lie, until they become a person, that lacks true integrity though they might be quite skilled as acting as if they have such. A person of real principle, does not tell lies, because they do not desire to become something that is un-pure, dirty and hypocritical, but rather will make their stand in the here and now, and thereby suffer what must be suffered, rather than postpone and let fester and grow that which destroys them from within.