— Independent Investigation of Truth

First, it is incumbent upon all mankind to investigate truth. If such investigation be made, all should agree and be united, for truth or reality is not multiple; it is not divisible. The different religions have one truth underlying them; therefore, their reality is one… But the people of the world have forsaken the divine teachings and followed forms and imitations of the truth. Inasmuch as these human interpretations and superstitions differ, dissensions and bigotry have arisen, and strife and warfare have prevailed. By investigating the truth or foundation of reality underlying their own and other beliefs, all would be united and agreed, for this reality is one; it is not multiple and not divisible.
— Abdu’l-Bahá

— The Oneness of Mankind

The second principle or teaching of Bahá’u’lláh is the proclamation of the oneness of the world of humanity–that all are servants of God and belong to one family; that God has created all and, therefore, His bestowals are universal; and that His providence, training, sustenance and loving-kindness surround all mankind.
This is the divine policy, and it is impossible for man to lay the foundation of a better plan and policy than that which God has instituted. Therefore, we must recognize and assist the purpose of the glorious Lord. Inasmuch as God is kind and loving to all, why should we be unkind? As this human world is one household, why should its members be occupied with animosity and contention? Therefore, humanity must be looked upon with the eye of equal estimate and in the same attitude of love. The noblest of men is he who serves humankind, and he is nearest the threshold of God who is the least of His servants. The glory and majesty of man are dependent upon his servitude to his fellow creatures and not upon the exercise of hostility and hatred.
— Abdu’l-Bahá

— The Unity of Science and Religion

The third principle or teaching of Bahá’u’lláh is the oneness of religion and science. Any religious belief which is not conformable with scientific proof and investigation is superstition, for true science is reason and reality, and religion is essentially reality and pure reason; therefore, the two must correspond. Religious teaching which is at variance with science and reason is human invention and imagination unworthy of acceptance, for the antithesis and opposite of knowledge is superstition born of the ignorance of man. If we say religion is opposed to science, we lack knowledge of either true science or true religion, for both are founded upon the premises and conclusions of reason, and both must bear its test.
— Abdu’l-Bahá

— A Spiritual Solution to the Economic Problem

The fourth principle or teaching of Bahá’u’lláh is the readjustment and equalization of the economic standards of mankind. This deals with the question of human livelihood. It is evident that under present systems and conditions of government the poor are subject to the greatest need and distress while others more fortunate live in luxury and plenty far beyond their actual necessities. This inequality of portion and privilege is one of the deep and vital problems of human society. That there is need of an equalization and apportionment by which all may possess the comforts and privileges of life is evident. The remedy must be legislative readjustment of conditions. The rich too must be merciful to the poor, contributing from willing hearts to their needs without being forced or compelled to do so. The composure of the world will be assured by the establishment of this principle in the religious life of mankind
— Abdu’l-Bahá

— The Abolition of Prejudice

The fifth principle or teaching of Bahá’u’lláh is the abandoning of religious, racial, patriotic and political prejudices, which destroy the foundations of human society. All mankind are creatures and servants of the one God. The surface of the earth is one home; humanity is one family and household. Distinctions and boundaries are artificial, human. Why should there be discord and strife among men? All must become united and coordinated in service to the world of humanity.
— Abdu’l-Bahá

— The Equality of Men and Women

The sixth principle or teaching of Bahá’u’lláh concerns the equality of man and woman. He has declared that in the estimation of God there is no distinction of sex. The one whose heart is most pure, whose deeds and service in the Cause of God are greater and nobler, is most acceptable before the divine threshold — whether male or female. In the vegetable and animal kingdoms sex exists in perfect equality and without distinction or invidious estimate. The animal, although inferior to man in intelligence and reason, recognizes sex equality. Why should man, who is endowed with the sense of justice and sensibilities of conscience, be willing that one of the members of the human family should be rated and considered as subordinate? Such differentiation is neither intelligent nor conscientious; therefore, the principle of religion has been revealed by Bahá’u’lláh that woman must be given the privilege of equal education with man and full right to his prerogatives. That is to say, there must be no difference in the education of male and female in order that womankind may develop equal capacity and importance with man in the social and economic equation. Then the world will attain unity and harmony. In past ages humanity has been defective and inefficient because it has been incomplete. War and its ravages have blighted the world; the education of woman will be a mighty step toward its abolition and ending, for she will use her whole influence against war. Woman rears the child and educates the youth to maturity. She will refuse to give her sons for sacrifice upon the field of battle. In truth, she will be the greatest factor in establishing universal peace and international arbitration. Assuredly, woman will abolish warfare among mankind. Inasmuch as human society consists of two parts, the male and female, each the complement of the other, the happiness and stability of humanity cannot be assured unless both are perfected. Therefore, the standard and status of man and woman must become equalized.
— Abdu’l-Bahá

— Universal Education

Among other teachings and principles Bahá’u’lláh counsels the education of all members of society. No individual should be denied or deprived of intellectual training, although each should receive according to capacity. None must be left in the grades of ignorance, for ignorance is a defect in the human world. All mankind must be given a knowledge of science and philosophy — that is, as much as may be deemed necessary. All cannot be scientists and philosophers, but each should be educated according to his needs and deserts.
— Abdu’l-Bahá

— Religion Must Be the Cause for Unity

Bahá’u’lláh teaches that the world of humanity is in need of the breath of the Holy Spirit, for in spiritual quickening and enlightenment true oneness is attained with God and man. The Most Great Peace cannot be assured through racial force and effort; it cannot be established by patriotic devotion and sacrifice; for nations differ widely and local patriotism has limitations. Furthermore, it is evident that political power and diplomatic ability are not conducive to universal agreement, for the interests of governments are varied and selfish; nor will international harmony and reconciliation be an outcome of human opinions concentrated upon it, for opinions are faulty and intrinsically diverse. Universal peace is an impossibility through human and material agencies; it must be through spiritual power. There is need of a universal impelling force which will establish the oneness of humanity and destroy the foundations of war and strife. None other than the divine power can do this; therefore, it will be accomplished through the breath of the Holy Spirit.

   —  Abdu’l-Bahá

— Oneness of Religion

There can be no doubt whatever that the peoples of the world, or whatever race of religion, derive their inspiration from one heavenly Source, and are the subjects of one God. The difference between the ordinances under which they abide should be attributed to the varying requirements and exigiencies of the age in which they were revealed. All of them, except a few which are the outcome of human perversity, were ordained of God, and are a reflection of His Will and Purpose.

   —  Abdu’l-Bahá

— Universal Peace

The earth is but one country and mankind its citizens.

That one indeed is a man who today dedicateth himself to the service of the entire human race. The Great Being saith: Blessed and happy is he that ariseth to promote the best interests of the peoples and kindreds of the earth.

   —  Bahá’u’lláh

— International Tribunal

True civilization will unfurl its banner in the midmost heart of the world whenever a certain number of its distinguished and high-minded sovereigns, the shining exemplars of devotion and determination, shall, for the good and happiness of all mankind, arise, with firm resolve and clear vision, to establish the Cause for Universal Peace. They must make the Cause of Peace the object of general consultation, and seek by every means in their power to establish a Union of the nations of the world. They must conclude a binding treaty and establish a covenant, the provisions or which shall be sound, inviolable and definite. They must proclaim it to all the world and obtain for it the sanction of all the human race. This supreme and noble undertaking, the real source of the peace and well-being of all the world, should be regarded as sacred by all that dwell on earth.
— Abdu’l-Bahá

— Universal Language

The day is approaching when all the peoples of the world will have adopted one universal language and one common script. When this is achieved, to whatsoever city a man may journey, it shall be as if he were entering his own home. These things are obligatory and absolutely essential. It is incumbent upon every man of insight and understanding to strive to translate that which hath been written into reality and action.

   —  Bahá’u’lláh