The Prophet ﷺ said, "Truthfulness leads to righteousness, and righteousness leads to Paradise. A man keeps speaking the truth until he is recorded with Allah as truthful. Lying leads to wickedness, and wickedness leads to the Fire. A man keeps lying until he is recorded with Allah as a liar."
عن النبي ﷺ قال: إن الصدق يهدي إلى البر، وإن البر يهدي إلى الجنة، وإن الرجل ليصدق حتى يكون صديقا، وإن الكذب يهدي إلى الفجور، وإن الفجور يهدي إلى النار، وإن الرجل ليكذب، حتى يكتب عند الله كذابا.
Bukhari narrated it in the Book of Manners (6094), and Muslim in the Book of Righteousness and Kinship Ties (2607), both of them from Uthman bin Abu Shayba, who said, Jareer narrated to us, from Mansur, from Abu Waail, from Abdullah, and he related it. The wording given is Bukhari's, and Muslim's wording is similar to it.As for His saying, "with the truthful", the first of them were the Prophet ﷺ and his companions who went out on the expedition to Tabuk. It is then general, applying to all the truthful who accepted the truth and remained steadfast upon it. As for the liar, he is not fit for companionship.