Allah has given us many wonderful gifts.Tongue is one of them.It is wonderful to be able to speak,  but we should see that everything we speak is true. Allah does not like the liars. Allah’s Messenger (saw) has said, “Be truthful. For truthfulness leads to piety and piety leads to paradise.If a man holds to truth and persisists in it; he will be recorded with Allah as a truthful man. Beware of lying. For lying leads to wickedness and wickedness leads to Hell. If a man lies and persists in it, he wwill be recorded with llah as a liar.”

Types of truthfulness:

Truthfulness may be classified into three types:

a) Truthfulness of speech

b) Truthfulness of action and

c) Truthfulness of intention

references :studies in Islam by Abdulaziz M.A