My answer is: It depends.
It depends on the person who is lying and what s/he wants to achieve by doing it. If someone lies for personal gain, to deceive and manipulate people in order to cause them harm; then it is wrong. We are all familiar with the concept of white lies. And no doubt many have tried to abuse the idea. But I believe that sometimes we have to do it in order to protect loved ones and ironically enough, to do the right thing. If the truth will hurt people and by exposing them will do nobody good and keeping them buried will not harm anyone, by all means lie.
Why we teach children not to lie? Because honesty is a fundamental basis of how a decent human being should be. Kids need to know the right set of rules first before they can break them when they are old enough to understand why sometimes they must do the opposite of what they have been taught. Like telling white lies for example.
In my book a good person is someone who has a good set of morals and values, who is aware of the difference between right and wrong, and who is honest to the core.
We all have to lie sometimes. But don’t lose sight of the valid reasons why we’re doing it. Often I wonder if omitting is the same as lying… I guess no matter what, the same rules still apply. Never do it in order to harm someone. Point.