"The different religions have one truth underlying them; therefore, their reality is one. Each of the divine religions embodies two kinds of ordinances. The first is those which concern spiritual susceptibilities, the development of moral principles and the quickening of the conscience of man. These are essential or fundamental, one and the same in all religions, changeless and eternal--reality is not subject to transformation. Abraham heralded this reality, Moses promulgated it, and Jesus Christ established it in the world of mankind. All the divine Prophets and Messengers were the instruments and channels of this same eternal, essential truth.

The second kind of ordinances in the divine religions is those which relate to the material affairs of humankind. These are the material or accidental laws which are subject to change in each day of manifestation, according to exigencies of the time, conditions and differing capacities of humanity....In brief, every one of the divine religions contains essential ordinances, which are not subject to change, and material ordinances, which are abrogated according to the exigencies of time. 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 Promulgation of Universal Peace, p. 105

"Religion is the light of the world, and the progress, achievement, and happiness of man result from obedience to the laws set down in the holy Books. Briefly, it is demonstrable that in this life, both outwardly and inwardly the mightiest of structures, the most solidly established, the most enduring, standing guard over the world, assuring both the spiritual and the material perfections of mankind, and protecting the happiness and the civilization of society--is religion.

It is true that there are foolish individuals who have never properly examined the fundamentals of the Divine religions, who have taken as their criterion the behavior of a few religious hypocrites and measured all religious persons by that yardstick, and have on this account concluded that religions are an obstacle to progress, a divisive factor and a cause of malevolence and enmity among peoples. They have not even observed this much, that the principles of the Divine religions can hardly be evaluated by the acts of those who only claim to follow them. For every excellent thing, peerless though it may be, can still be diverted to the wrong ends. A lighted lamp in the hands of an ignorant child or of the blind will not dispel the surrounding darkness nor light up the house--it will set both the bearer and the house on fire. Can we, in such an instance, blame the lamp?" - 'Abdu'l-Baha, The Secret of Divine Civilization, p. 71

"True religion is the source of love and agreement amongst men, the cause of the development of praiseworthy qualities, but the people are holding to the counterfeit and imitation, negligent of the reality which unifies, so they are bereft and deprived of the radiance of religion. They follow superstitions inherited from their fathers and ancestors. To such an extent has this prevailed that they have taken away the heavenly light of divine truth and sit in the darkness of imitations and imaginations. That which was meant to be conducive to life has become the cause of death; that which should have been an evidence of knowledge is now a proof of ignorance; that which was a factor in the sublimity of human nature has proved to be its degradation. Therefore, the realm of the religionist has gradually narrowed and darkened, and the sphere of the materialist has widened and advanced; for the religionist has held to imitation and counterfeit, neglecting and discarding holiness and the sacred reality of religion." - 'Abdu'l-Bahá, The Promulgation of Universal Peace, p. 179