I think lying isn't in the overwhelming majority of cases necessary. Even if you should get some temporal gain, lying is destroying your personality bit by bit and eventually it will ruin your life, and lifes of those around you. In my opinion, if you think you can reach your goal by lie only, the goal most probably wasn't worth it and the people weren't worth it, if they are so weak or stupid that they can't put up with your truth. Compromising truth just in order to be liked by other people is cowardice. And people who can't accept truth are cowards. I think would lie only in emergency or if faced with really insane or dangerous person.
When we are at it, my mother is a big liar, she lies all the time and keeps advising me to do the same. It's always, "you can't say that, tell that.. (blah blah blah)". It's one thing why I have aversion towards her and don't respect her. By constant compromising the truth like this, she married an abusive idiot and never opposed to him, on the contrary supported and spoiled him. In the end this ruined predominantly MY life. Because of her weakness and not keeping to the truth.