Should i always tell the truth?

That's usually considered the best policy. Sometimes it can hurt people the truth though. Don't always tell people the truth, it's not always the best thing to do.

________

(Added by Chelseam2)

Sometimes telling the truth can hurt others.

Never tell a lie if it's for selfish personal gain.

Here is an example:

Did my child suffer before he died?

Would you tell a mother that? Really? Already grieving the lost of her kid, telling her he was in great anguish and pain wouldn't make it any better.

Another:

Spy, where are your troups hidden? (So we may kill them...)

That would conclude of loss of life.