Why do people tell lies?

I agree that in every lie there would always come pain but if you use the lie to protect somebody, would the means justify the end? Losing somebody is a fear that everyone has and telling the truth has never been helpful in that, what if you had to lie to spare someones feeling, would it be wrong to do that? If you are not telling the truth because you are cheating on somebody, then that would be wrong but what if you are telling them a lie so that they would not get hurt like if your wife asks you if she's fat, would you be able to tell her the truth? I think a little lie in life helps as long as its not that major.

People tell lies to deceive, and to avoid others from the truth. It is the basic reason why do people tell lies. Lies can misguide and mislead the listener into a wrong notion and deviate from correct perception to benefit the liar.