Answer: Truthfulness means saying what conforms with the reality or what is true.
Examples include:
. Truthfulness in talking with people
. Truthfulness in making a promise
. Truthfulness in every word and deed
The Prophet (may Allah's peace and blessings be upon him) said: "Adhere to truthfulness, for truthfulness leads to righteousness and righteousness leads to Paradise. A man will keep speaking the truth until he becomes of the most truthful." [Agreed upon]