Al-A'mash (may Allah have mercy on him) narrates with his chain: "A person continues to speak the truth and to strive for truthfulness until he is written among the truthful with Allah." And in another narration it says: "A person continues to lie and to strive for lying until he is counted among the liars with Allah."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 20818