All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
Truthfulness is, indeed, a great moral value and refined character trait; it is one of the divine attributes of Allah, The Exalted. He says (what means): {Say: Allah has told the truth. So follow the religion of Ibraaheem, inclining toward truth; and he was not of the polytheists.} [Quran 3:95]
Truthfulness is one of the refined character traits of the Prophet, sallallaahu ʻalayhi wa sallam. Ibn Masʻood said, “The Messenger of Allah the truthful and trustworthy, informed us that...” [Al-Bukhari and Muslim]
Truthfulness yields many good effects in society, some of which are:
Firstly, the spread of goodness and virtue in the society, which leads to the elimination of evil and vice. Ibn Masʻood reported that the Prophet said, “Adhere to truthfulness, for truthfulness leads to righteousness, and righteousness leads to Paradise. A man keeps on telling the truth until he is recorded with Allah as truthful...” [Muslim]
Secondly, earning the blessings of Allah in one's wealth. Indeed, whatever Allah blesses yields much benefit. Hakeem ibn Hizaam narrated that the Prophet said, “Both parties in a business transaction have a right to annul it so long as they have not separated; and if they tell the truth and make everything clear to each other, then they will be blessed in their transaction, but if they conceal anything and lie, then their transaction will be deprived of the blessings of Allah.” [Al-Bukhari and Muslim]
Thirdly, serenity and tranquility prevail in the society, along with mutual trust and confidence among its members. Al-Hasan ibn ʻAli said, “Give up what is doubtful to you for that which is not doubtful; for truth is peace of mind and falsehood is doubt.” [At-Tirmithi]
Allah knows best.