“…religion is the teachings of the Lord God…”

Religion… is not a series of beliefs, a set of customs; religion is the teachings of the Lord God, teachings which constitute the very life of humankind, which urge high thoughts upon the mind, refine the character, and lay the groundwork for man’s everlasting honour. 
- 'Abdu'l-Bahá  (‘Selections from the Writings of 'Abdu'l-Bahá’)

The human soul’s “progress and success, in all the worlds of God” is dependent on the virtue of ”truthfulness”

Truthfulness is the foundation of all human virtues. Without truthfulness progress and success, in all the worlds of God, are impossible for any soul. When this holy attribute is established in man, all the divine qualities will also be acquired.  
- ‘Abdu’l-Baha  (Quoted by Shoghi Effendi, ‘The Advent of Divine Justice’) 

How to treat each other

Beware lest ye harm any soul, or make any heart to sorrow; lest ye wound any man with your words, be he known to you or a stranger, be he friend or foe. Pray ye for all; ask ye that all be blessed, all be forgiven. Beware, beware, lest any of you seek vengeance, even against one who is thirsting for your blood. Beware, beware, lest ye offend the feelings of another, even though he be an evil-doer, and he wish you ill. Look ye not upon the creatures, turn ye to their Creator. See ye not the never-yielding people, see but the Lord of Hosts. Gaze ye not down upon the dust, gaze upward at the shining sun, which hath caused every patch of darksome earth to glow with light. 
- 'Abdu'l-Bahá  (‘Selections from the Writings of 'Abdu'l-Bahá’)

God has “endowed every soul with the capacity to recognize the signs of God”

He [God] hath endowed every soul with the capacity to recognize the signs of God. How could He, otherwise, have fulfilled His testimony unto men, if ye be of them that ponder His Cause in their hearts. He will never deal unjustly with any one, neither will He task a soul beyond its power. He, verily, is the Compassionate, the All-Merciful. 
- Baha'u'llah  (Gleanings from the Writings of Baha'u'llah)

A general rule to guide one’s life...

O thou dear handmaid of God! Thy letter hath been received and its contents noted. Thou didst ask for a rule whereby to guide thy life.

Believe thou in God, and keep thine eyes fixed upon the exalted Kingdom; be thou enamoured of the Abhá Beauty; stand thou firm in the Covenant; yearn thou to ascend into the Heaven of the Universal Light. Be thou severed from this world, and reborn through the sweet scents of holiness that blow from the realm of the All-Highest. Be thou a summoner to love, and be thou kind to all the human race. Love thou the children of men and share in their sorrows. Be thou of those who foster peace. Offer thy friendship, be worthy of trust. Be thou a balm to every sore, be thou a medicine for every ill. Bind thou the souls together. Recite thou the verses of guidance. Be engaged in the worship of thy Lord, and rise up to lead the people aright. Loose thy tongue and teach, and let thy face be bright with the fire of God’s love. Rest thou not for a moment, seek thou to draw no easeful breath. Thus mayest thou become a sign and symbol of God’s love, and a banner of His grace. 
- ‘Abdu’l-Baha  (‘Selections from the Writings of ‘Abdu’l-Baha’) 

“Consort with all the peoples, kindreds and religions of the world with the utmost truthfulness, uprightness, faithfulness, kindliness, good-will and friendliness…”

Wherefore, O my loving friends! Consort with all the peoples, kindreds and religions of the world with the utmost truthfulness, uprightness, faithfulness, kindliness, good-will and friendliness, that all the world of being may be filled with the holy ecstasy of the grace of Bahá, that ignorance, enmity, hate and rancor may vanish from the world and the darkness of estrangement amidst the peoples and kindreds of the world may give way to the Light of Unity. Should other peoples and nations be unfaithful to you show your fidelity unto them, should they be unjust toward you show justice towards them, should they keep aloof from you attract them to yourselves, should they show their enmity be friendly towards them, should they poison your lives, sweeten their souls, should they inflict a wound upon you, be a salve to their sores. Such are the attributes of the sincere! Such are the attributes of the truthful. 
- ‘Abdu’l-Baha  (‘The Will and Testament of ‘Abdu’l-Baha’)

"The foundation of the divine religions is reality"

The foundation of the divine religions is reality; were there no reality, there would be no religions. Abraham heralded reality. Moses promulgated reality. Christ established reality. Muhammad was the Messenger of reality. The Báb was the door of reality. Bahá’u’lláh was the splendor of reality. Reality is one; it does not admit multiplicity or division. Reality is as the sun, which shines forth from different dawning points; it is as the light, which has illumined many lanterns. (‘Abdu’l-Baha, from a talk, 19 May, 1912, New York; ‘The Promulgation of Universal Peace: Talks Delivered by Abdu'l-Bahá during His Visit to the United States and Canada in 1912’)

We should adhere to the spiritual laws revealed to humanity in each age by the Manifestation of God the same way that we pay attention to laws governing our physical lives

Just as there are laws governing our physical lives, requiring that we must supply our bodies with certain foods, maintain them within a certain range of temperatures, and so forth, if we wish to avoid physical disabilities, so also there are laws governing our spiritual lives. These laws are revealed to mankind in each age by the Manifestation of God, and obedience to them is of vital importance if each human being, and mankind in general, is to develop properly and harmoniously. Moreover, these various aspects are interdependent. If an individual violates the spiritual laws for his own development he will cause injury not only to himself but to the society in which he lives. Similarly, the condition of society has a direct effect on the individuals who must live within it. (The Universal House of Justice, from a letter dated 6 February 1973 to all National Spiritual Assemblies; ‘Messages from the Universal House of Justice 1968-1973’; The Compilation of Compilations, vol. I, A Chase and Holy Life)

The Prophets come to this world to help us educate our own souls

The Prophets have appeared in this world with the mission that human souls may become the expressions of the Merciful, that they may be educated and developed, attain to love and amity and establish peace and agreement. (‘Abdu’l-Baha, excerpt from a talk given on 21 April 1912 in Washington D.C.; The Promulgation of Universal Peace) (To read the entire talk please visits Talks of ‘Abdu’l-Baha)

The teachings, proofs and evidences of the divine Manifestations (Prophets) are one -- They differ in name and form “but in reality They agree and are the same.”

The divine Manifestations since the day of Adam have striven to unite humanity so that all may be accounted as one soul. The function and purpose of a shepherd is to gather and not disperse his flock. The Prophets of God have been divine Shepherds of humanity. They have established a bond of love and unity among mankind, made scattered peoples one nation and wandering tribes a mighty kingdom. They have laid the foundation of the oneness of God and summoned all to universal peace. All these holy, divine Manifestations are one. They have served one God, promulgated the same truth, founded the same institutions and reflected the same light. Their appearances have been successive and correlated; each One has announced and extolled the One Who was to follow, and all laid the foundation of reality. They summoned and invited the people to love and made the human world a mirror of the Word of God. Therefore, the divine religions They established have one foundation; Their teachings, proofs and evidences are one; in name and form They differ, but in reality They agree and are the same. (‘Abdu’l-Baha, excerpt from a talk, 28 May 1912, New York; ‘The Promulgation of Universal Peace’)

God’s Prophets have always been “the intermediary” through Whom we receive everything from God

…the Apostles and Messengers of God have ever been the channels of His abounding grace, and whatsoever man hath received from God hath been through the intermediary of those Embodiments of holiness and Essences of detachment, those Repositories of His knowledge and Exponents of His Cause. (Baha’u’llah,‘The Tabernacle of Unity)

“…every child must learn reading and writing, and acquire such branches of knowledge as are useful and necessary, as well as learning an art or skill.”

And further, according to the Divine commandments, every child must learn reading and writing, and acquire such branches of knowledge as are useful and necessary, as well as learning an art or skill. The utmost care must be devoted to these matters; any neglect of them, any failure to act on them, is not permissible. (‘Abdu'l-Bahá from a Tablet; The Compilation of Compilations, Vol. I, The Arts and Crafts)

We shouldn’t magnify our accomplishments

A man who does great good, and talks not of it, is on the way to perfection. 

The man who has accomplished a small good and magnifies it in his speech is worth very little. (‘Abdu’l-Baha, from a talk, October 16, 1911, ‘Paris Talks’)