There are two kinds of people: those who lie only when the occasion calls for it, and those who tell the truth only when it suits their purposes. Those who always tell the truth, no matter what, because that wins them the favor of a god, or their mother, or whatever, are in the latter category. Their purpose is winning that favor.
There are times when the right thing to do is lie. The classic example is telling the Nazis that of course there are no Jews hiding in your house. You haven’t seen any Jews lately. No Jews around here, that’s for sure. A more current example could be telling your neighbor that you have no idea where his wife is, although you know she sought refuge to escape his abuse. There are times when too much honesty can get somebody killed.
It makes sense, then, that you should learn how to be a good liar, just for those occasions. An honest person is not one who never lies, but one who only lies to prevent harm. Yet most of us have been taught to feel guilty for telling any kind of lie, even one intended to protect the innocent. That makes it more difficult for us to lie convincingly when it is called for. Maybe, instead of punishing our kids for lying, we should be teaching them how to determine which things they should be upfront about, and which things are appropriate to conceal. And under what circumstances it is right to boldly lie.
Learning to be a responsible member of society is complicated, in part because “society” is often irresponsible. We like to think that we can always trust the authorities to do the right thing, but we know that they often do not. Because of that, it is dangerous to invariably tell the truth. When the situation calls for it, it is much better lie deliberately, being well aware of the difference between truth and fiction, and being comfortable that it is the right thing to do.