Never tell lie -It is not good to tell lie because we have listen the poetry 'for hiding one lie we have to speak 100 lies'. And sometimes we hide some trouble from elders and regret
after that.And this is also said by Mahatma Gandhi.
Sometime is good to tell lie to save someone's life or job. For e.g. someone had make a mistake in ur class that is not very big so you can forgive him\her if he\she is saying sorry to u and saying that will not repeat this mistake.And it can same him\her from teacher's scolding for very small mistake.