Truthfulness

That Allah may reward the truthful for their truth and punish the hypocrites if He wills or accept their repentance. Indeed, Allah is ever Forgiving and Merciful.
Surat Al-Ahzab 33:24

O you who have believed, fear Allah and be with those who are true.
Surat At-Tawbah 9:119

O you who have believed, fear Allah and speak words of appropriate justice.
Surat Al-Ahzab 33:40

Say, “Shall I inform you of [something] better than that? For those who fear Allah will be gardens in the presence of their Lord beneath which rivers flow, wherein they abide eternally, and purified spouses and approval from Allah . And Allah is Seeing of [His] servants – Those who say, “Our Lord, indeed we have believed, so forgive us our sins and protect us from the punishment of the Fire,” The patient, the true, the obedient, those who spend [in the way of Allah ], and those who seek forgiveness before dawn.
Surat Al-e-Imran 3:15-17

The believers are only the ones who have believed in Allah and His Messenger and then doubt not but strive with their properties and their lives in the cause of Allah . It is those who are the truthful.
Surat Al-Hujurat 49:15