Man must live a virtuous life.
243. Virtue, one of the teachings found in all the religions of God is that man must live a virtuous life if he wishes to achieve his true spiritual potential in this existence; and virtue is an absolute must for man’s progress in the next world: 
Baha’i Faith: “By my life! Man’s distinction lieth not in ornaments or wealth, but rather in virtuous behaviour and true understanding.” “The sword of a virtuous character and upright conduct is sharper than blades of steel.” “Virtue is not a matter of thoughts and words. It must find expression in acts.”
(Bahá’í Faith, Baha’u’llah, Tablets of Baha’u’llah, p. 57 and Epistle to the Son of the Wolf, p. 29) (ZOROASTER, Hymns of Atharvan p. 187)
CHRISTIANITY: Philippians 4:8 “Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.” 2 Peter 1:1 “Simon Peter, a servant and an apostle of Jesus Christ, to them that have obtained like precious faith with us through the righteousness of God and our Saviour Jesus Christ:” 2 Peter 1:2 “Grace and peace be multiplied unto you through the knowledge of God, and of Jesus our Lord,” 2 Peter 1:3 “According as His divine power hath given unto us all things that pertain unto life and godliness, through the knowledge of him that hath called us to glory and virtue:” 2 Peter 1:4 “Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust.” 2 Peter 1:5 “And beside this, giving all diligence, add to your faith virtue; and to virtue knowledge;” 2 Peter 1:6 “And to knowledge temperance; and to temperance patience; and to patience godliness;” 2 Peter 1:7 “And to godliness brotherly kindness; and to brotherly kindness charity.” 
Judaism: Psalms 24:4 “He that hath clean hands, and a pure (virtuous) heart; who hath not lifted up his soul unto vanity, nor sworn deceitfully.” Psalms 24:5 “He shall receive the blessing from The LORD.” Wisdom 8:7 “And if a man love righteousness her labours are virtues: for she teacheth temperance and prudence, justice and fortitude: which are such things, as then can have nothing more profitable in their life.” (Deuterocanonical Apocrypha)
ISLAM: Letters 30 and 45 “The Merciful Allah (God) has shown you the correct way of leading an honest and a virtuous life and has clearly pointed to you the place where life and its activities are going to end.” “Shall I not set an example for them to patiently, courageously and virtuously bear privation?” “Advise people to do good and to live virtuously.”
(Islam, Ali b. Abi Taalib, Letters from Nahjul Balaagh)
Islam: 48. “If Allah had so willed, He would have made you a single people, but (His plan is) to test you in what He hath given you: so strive as in a race in all virtues.”
(The Qur’an (Yusuf Ali tr), Surah 5)
Islam: 29 “But if ye desire God and His Apostle, and a home in the next life, then, truly, hath God prepared for those of you who are virtuous, a great reward.”
(The Qur’an (Rodwell tr), Sura 33 – The Confederates)
Islam: 29. “But if ye seek Allah and His Messenger, and the Home of the Hereafter, verily Allah has prepared for the well-doers (the virtuous) amongst you a great reward.”
(The Qur’an (Yusuf Ali tr), Surah 33)
ZOROASTRIANISM: Denkard. Zoroaster, “There comes a day, O Spitama Zarathustra! or a night, when the master leaves the cattle, or the cattle leave the master, or the soul leaves that body full of desires;” “But his virtue, which is of all existences the greatest, the best, the finest, never parts from a man.” “Various persons prevail in goodness through virtue.”
(Zoroaster, The Zend-Avesta, Avesta Fragments and Denkard)
Zoroastrianism: “For the reward of virtue and the forgiveness of sins, I do (deeds of) righteousness for the love of my soul. May all virtuousness of all good ones of the earth of seven climes reach the width of the earth, the length of the rivers, the height of the sun in their original form. May it be righteous, live long. Thus may it come as I wish.”
(Zoroaster, The Zend-Avesta, Khorda Avesta – Book of Common Prayer pt. 1)
Zoroastrianism: “Virtue for the sake of virtue, and not for the sake of anything else (like pleasure, fame etc…) is the end (and) rectitude is the first step towards God-realization; for rectitude is the first manifestation of Mazda (God).” (ZOROASTER, Hymns of Atharvan)
Zoroastrianism: “Mazda is the upholder of rectitude. The more virtuous a man is the nearer he comes to Mazda, the source of perpetual delight.” (ZOROASTER, Hymns of Atharvan p. 580)
HINDUISM: “I come, and go, and come. When Righteousness Declines, O Bharata! when Wickedness Is strong, I rise, from age to age, and take Visible shape, and move a man with men, Succouring the good, thrusting the evil back, And setting Virtue on her seat again.
(Hindu, Bhagavad Gita (Edwin Arnold tr) chapter 4)
Hinduism: 1. “Learn that sacred law which is followed by men learned (in the Veda) and assented to in their hearts by the virtuous, who are ever exempt from hatred and inordinate affection.” 334. “For virtue is the highest duty.”
(Hindu, Laws of Manu chapter 2 and 9)
Hinduism: 155. “Let him, untired, follow the conduct of virtuous men, which has been fully declared in the revealed texts and in the sacred tradition (Smriti) and is the root of the sacred law.” 156. “Through virtuous conduct he obtains long life, through virtuous conduct desirable offspring, through virtuous conduct imperishable wealth; virtuous conduct destroys (the effect of) inauspicious marks.” 240. “Single is each being born; single it dies; single it enjoys (the reward of it’s) virtue; single (it suffers the punishment of its) sin.”
(Hindu, Laws of Manu chapter 4)
Hinduism: 20. “If (the soul) chiefly practices virtue and vice to a small degree, it obtains bliss in heaven, clothed with those very elements.” “With deep devotion and with faultless faith obey, Truth and virtue on thy bosom ever hold their gentle sway.”
(Hindu, Laws of Manu chapter 12 and Ramayana)
BUDDHISM: “One should cherish ideals of charity, good behavior, patience, zeal, thoughtfulness and wisdom. Even in the worldly life the practice of these virtues will bring rewards of happiness and success.” (Buddha, Lankavatara Sutra)
Buddhism: 4. “Sandalwood or rose-bay or lotus or jasmine among these perfumes, the perfume of virtue is unsurpassed. Limited is the scent of rose-bay or sandalwood; but the perfume of the virtuous rises up to the gods as the highest.”
(Buddhist, Dhammapada – Sayings of the Buddha 2 (tr. J. Richards))
Buddhism: 12. “Arise; do not be thoughtless. Follow the path of virtue. The virtuous rest in bliss in this world and in the next. Follow the path of virtue; do not follow the wrong path. The virtuous rest in bliss in this world and in the next.”
(Buddhist, Dhammapada – Sayings of the Buddha 2 (tr. J. Richards))
SABEANISM: “(Hear) the prayers of spirits and souls of righteous and believing men, the virtuous and well pleasing (followers).” (SABEANISM, Ginza Rba- Chapter 8)
Sabeanism: “Let healing be theirs by virtue.” (Sabeanism, Ginza Rba- chapter 20)
BABI RELIGION: “O all ye created things! Strive to gain admittance into Paradise, since ye have, during all your lives, held fast unto virtuous deeds.”
(The Bab, Selections from the Writings of the Bab, p. 144)
BAHA’I FAITH: “In the Book of Utterance these exalted words have been written down and recorded: ‘Say, O friends! Strive that haply the tribulations suffered by this Wronged One and by you, in the path of God, may not prove to have been in vain. Cling ye to the hem of virtue, and hold fast to the cord of trustworthiness and piety. Concern yourselves with the things that benefit mankind, and not with your corrupt and selfish desires. O ye followers of this Wronged One! Ye are the shepherds of mankind; liberate ye your flocks from the wolves of evil passions and desires, and adorn them with the ornament of the fear of God. This is the firm commandment which hath, at this moment, flowed out from the Pen of Him Who is the Ancient of Days. By the righteousness of God! The sword of a virtuous character and upright conduct is sharper than blades of steel. The voice of the true Faith calleth aloud, at this moment, and saith: O people! Verily, the Day is come, and My Lord hath made Me to shine forth with a light whose splendor hath eclipsed the suns of utterance. Fear ye the Merciful, and be not of them that have gone astray.”
(Bahá’í Faith, Baha’u’llah, Epistle to the Son of the Wolf, p. 28)
BABI RELIGION: “You who are His spiritual children must by your deeds exemplify His virtues, and witness to His glory.”
(H. M. Balyuzi, The Bab – The Herald of the Days, p. 29)
BAHA’I FAITH: “In one of the Tablets these words have been revealed: O people of God! Do not busy yourselves in your own concerns; let your thoughts be fixed upon that which will rehabilitate the fortunes of mankind and sanctify the hearts and souls of men. This can best be achieved through pure and holy deeds, through a virtuous life and a goodly behavior. Valiant acts will ensure the triumph of this Cause, and a saintly character will reinforce its power. Cleave unto righteousness, O people of Baha! This, verily, is the commandment which this wronged One hath given unto you, and the first choice of His unrestrained Will for every one of you.”
(Bahá’í Faith, Baha’u’llah, Gleanings from the Writings of Baha’u’llah, p. 93)
BABI RELIGION: “Purge your hearts of worldly desires, and let angelic virtues be your adorning.”
(H. M. Balyuzi, The Bab – The Herald of the Days, p. 29)
BAHA’I FAITH: “Honesty, virtue, wisdom and a saintly character redound to the exaltation of man, while dishonesty, imposture, ignorance and hypocrisy lead to his abasement. By My life! Man’s distinction lieth not in ornaments or wealth, but rather in virtuous behaviour and true understanding.”
(Bahá’í Faith, Baha’u’llah, Tablets of Baha’u’llah, p. 57)