Why speak the truth?
To establish my uniqueness, I think. This is the first true service which I can give not only to myself but also to others around me. They need not guess who I am.
Speaking the truth is in itself a manifestation or overflow of being true. Even at the level of lying in words, one can say lies by exaggerating, by uttering partial truths, by using embellishments. How difficult it is not to get caught in it.
Then the ever present enemy of truth in the modern world. "You are a fool! everybody does it."
The one who practices truth should hold on firmly to the knowledge that HE OR SHE IS NOT A FOOL BUT SOMEONE HEROIC.