Is lying if ever justified?

Actually, most of us start lying in the childhood while saying "I don't know anything, I didn't take sweets from the table" not to be punished or prohibited doing something. So maybe it is one of the traits of human nature. And while we are kids it may look even funny, such tiny obvious lies. But as soon as we grow up and the things to lie about become serious, there occurs the question "Is lying if ever justified?"...
I think sometimes it is. There is a notion called "white lie" when you lie not to hurt one's feelings or not to worry your parents, for example. Another version is lying by omission, when you just hold back something, for example, not telling everything about your property to the person you are hardly familiar with if he/she asks you. The thing is try to predict the consequences of your lying, to imagine the reaction, the feelings of people, whom you lied, if your dishonesty will ever be revealed. Will it really be understood and forgiven?