Truth and Lying

Abdullah bin Mas’ud (Radhi Allahu Anhu) said that the Messenger of Allah (Sallallahu Alayhi wa Sallam) said,

Hold on to truth, for being truthful leads to righteousness, and righteousness leads to Paradise. Verily, a man will keep saying the truth and striving for truth, until he is written before Allah as very truthful (Siddiq). Beware of lying, for lying leads to sin, and sin leads to the Fire. Verily, the man will keep lying and striving for falsehood until he is written before Allah as a great liar. (Al-Bukhari and Muslim)