Duty to Consult in All Things:
Take ye counsel together in all matters, inasmuch as consultation is the lamp of guidance which leadeth the way, and is the bestower of understanding.
(Baha’u’llah: Tablets of Baha’u’llah, p. 168)

In all things it is necessary to consult. This matter should be forcibly stressed by thee, so that consultation may be observed by all. The intent of what hath been revealed from the Pen of the Most High is that consultation may be fully carried out among the friends, inasmuch as it is and will always be a cause of awareness and of awakening and a source of good and well-being.
(Baha’u’llah: Consultation, p. 93)

Settle all things, both great and small, by consultation. Without prior consultation, take no important step in your own personal affairs.
(`Abdu’l-Baha: Consultation, p. 98)

Regarding thy question about consultation of a father with his son, or a son with his father, in matters of trade and commerce, consultation is one of the fundamental elements of the foundation of the Law of God. Such consultation is assuredly acceptable, whether between father and son, or with others. There is nothing better than this. Man must consult in all things for this will lead him to the depths of each problem and enable him to find the right solution.
(`Abdu’l-Baha: Consultation, p. 98)

For instance, when a man hath a project to accomplish, should he consult with some of his brethren, that which is agreeable will of course be investigated and unveiled to his eyes, and the truth will be disclosed. Likewise on a higher level, should the people of a village consult one another about their affairs, the right solution will certainly be revealed. In like manner, the members of each profession, such as in industry, should consult, and those in commerce should similarly consult on business affairs. In short, consultation is desirable and acceptable in all things and on all issues.
(`Abdu’l-Baha: Consultation, p. 98)

The principle of consultation, which constitutes one of the basic laws of the Administration, should be applied to all Baha’i activities which affect the collective interests of the Faith, for it is through co-operation and continual exchange of thoughts and views that the Cause can best safeguard and foster its interests. Individual initiative, personal ability and resourcefulness, though indispensable, are, unless supported and enriched by the collective experiences and wisdom of the group, utterly incapable of achieving such a tremendous task.
(Shoghi Effendi: Consultation, pp. 103-104)

Goals and Benefits:
Man must consult on all matters, whether major or minor, so that he may become cognizant of what is good. Consultation giveth him insight into things and enableth him to delve into questions which are unknown. The light of truth shineth from the faces of those who engage in consultation. Such consultation causeth the living waters to flow in the meadows of man’s reality, the rays of ancient glory to shine upon him, and the tree of his being to be adorned with wondrous fruit. The members who are consulting, however, should behave in the utmost love, harmony and sincerity towards each other. The principle of consultation is one of the most fundamental elements of the divine edifice. Even in their ordinary affairs the individual members of society should consult.
(`Abdu’l-Baha: Consultation, p. 97)

…consultation must have for its object the investigation of truth.
(`Abdu’l-Baha: Promulgation of Universal Peace, p. 72)

The purpose of consultation is to show that the views of several individuals are assuredly preferable to one man, even as the power of a number of men is of course greater than the power of one man.
(`Abdu’l-Baha: Consultation, p. 97)

It should be borne in mind that all consultation is aimed at arriving at a solution to a problem…
(The Universal House of Justice: Lights of Guidance, p. 179)

Guidelines for Consultation:
The prime requisites for them that take counsel together are purity of motive, radiance of spirit, detachment from all else save God, attraction to His Divine Fragrances, humility and lowliness amongst His loved ones, patience and long-suffering in difficulties and servitude to His exalted Threshold. Should they be graciously aided to acquire these attributes, victory from the unseen Kingdom of Baha shall be vouchsafed to them. In this day, assemblies of consultation are of the greatest importance and a vital necessity. Obedience unto them is essential and obligatory. The members thereof must take counsel together in such wise that no occasion for ill-feeling or discord may arise. This can be attained when every member expresseth with absolute freedom his own opinion and setteth forth his argument. Should any one oppose, he must on no account feel hurt for not until matters are fully discussed can the right way be revealed. The shining spark of truth cometh forth only after the clash of differing opinions. If after discussion, a decision be carried unanimously, well and good; but if, the Lord forbid, differences of opinion should arise, a majority of voices must prevail.
(`Abdu’l-Baha, quoted in Shoghi Effendi: Baha’i Administration, pp. 21-22)

The first condition is absolute love and harmony amongst the members of the assembly. They must be wholly free from estrangement and must manifest in themselves the Unity of God, for they are the waves of one sea, the drops of one river, the stars of one heaven, the rays of one sun, the trees of one orchard, the flowers of one garden. Should harmony of thought and absolute unity be non-existent, that gathering shall be dispersed and that assembly be brought to naught. The second condition: – They must when coming together turn their faces to the Kingdom on High and ask aid from the Realm of Glory. They must then proceed with the utmost devotion, courtesy, dignity, care and moderation to express their views. They must in every matter search out the truth and not insist upon their own opinion, for stubbornness and persistence in one’s views will lead ultimately to discord and wrangling and the truth will remain hidden. The honored members must with all freedom express their own thoughts, and it is in no wise permissible for one to belittle the thought of another, nay, he must with moderation set forth the truth, and should differences of opinion arise a majority of voices must prevail, and all must obey and submit to the majority. It is again not permitted that any one of the honored members object to or censure, whether in or out of the meeting, any decision arrived at previously, though that decision be not right, for such criticism would prevent any decision from being enforced. In short, whatsoever thing is arranged in harmony and with love and purity of motive, its result is light, and should the least trace of estrangement prevail the result shall be darkness upon darkness….
(`Abdu’l-Baha, quoted in Shoghi Effendi: Baha’i Administration, p. 22)

So they (members) must confer and consult in such a way that neither disagreement nor abhorrence may occur. When meeting for consultation, each must use perfect liberty in stating his views and unveiling the proof of his demonstration. If another contradicts him, he must not become excited because if there be no investigation or verification of questions and matters, the agreeable view will not be discovered neither understood. The brilliant light which comes from the collision of thoughts is the “lightener” of facts.
(`Abdu’l-Baha: Baha’i World Faith, p. 406)

He who expresses an opinion should not voice it as correct and right but set it forth as a contribution to the consensus of opinion, for the light of reality becomes apparent when two opinions coincide. A spark is produced when flint and steel come together. Man should weigh his opinions with the utmost serenity, calmness and composure. Before expressing his own views he should carefully consider the views already advanced by others. If he finds that a previously expressed opinion is more true and worthy, he should accept it immediately and not willfully hold to an opinion of his own. By this excellent method he endeavors to arrive at unity and truth. Opposition and division are deplorable. It is better then to have the opinion of a wise, sagacious man; otherwise, contradiction and altercation, in which varied and divergent views are presented, will make it necessary for a judicial body to render decision upon the question. Even a majority opinion or consensus may be incorrect. A thousand people may hold to one view and be mistaken, whereas one sagacious person may be right. Therefore, true consultation is spiritual conference in the attitude and atmosphere of love. Members must love each other in the spirit of fellowship in order that good results may be forthcoming. Love and fellowship are the foundation.
(`Abdu’l-Baha: Promulgation of Universal Peace, pp. 72-73)

…when a believer is uncertain about his affairs, or when he seeketh to pursue a project or trade, the friends should gather together and devise a solution for him. He, in his turn, should act accordingly. Likewise in larger issues, when a problem ariseth, or a difficulty occurreth, the wise should gather, consult, and devise a solution. They should then rely upon the one true God, and surrender to His Providence, in whatever way it may be revealed, for divine confirmations will undoubtedly assist.
(`Abdu’l-Baha: Consultation, pp. 96-97)

The ideal of Baha’i consultation is to arrive at a unanimous decision. When this is not possible a vote must be taken.
(The Universal House of Justice: Lights of Guidance, p. 47)

“The Most Memorable Instance”:
The most memorable instance of spiritual consultation was the meeting of the disciples of Jesus Christ upon the mount after His ascension. They said, “Jesus Christ has been crucified, and we have no longer association and intercourse with Him in His physical body; therefore, we must be loyal and faithful to Him, we must be grateful and appreciate Him, for He has raised us from the dead, He made us wise, He has given us eternal life. What shall we do to be faithful to Him?” And so they held council. One of them said, “We must detach ourselves from the chains and fetters of the world; otherwise, we cannot be faithful.” The others replied, “That is so.” Another said, “Either we must be married and faithful to our wives and children or serve our Lord free from these ties. We cannot be occupied with the care and provision for families and at the same time herald the Kingdom in the wilderness. Therefore, let those who are unmarried remain so, and those who have married provide means of sustenance and comfort for their families and then go forth to spread the message of glad tidings.” There were no dissenting voices; all agreed, saying, “That is right.” A third disciple said, “To perform worthy deeds in the Kingdom we must be further self-sacrificing. From now on we should forego ease and bodily comfort, accept every difficulty, forget self and teach the Cause of God.” This found acceptance and approval by all the others. Finally a fourth disciple said, “There is still another aspect to our faith and unity. For Jesus’ sake we shall be beaten, imprisoned and exiled. They may kill us. Let us receive this lesson now. Let us realize and resolve that though we are beaten, banished, cursed, spat upon and led forth to be killed, we shall accept all this joyfully, loving those who hate and wound us.” All the disciples replied, “Surely we will – it is agreed; this is right.” Then they descended from the summit of the mountain, and each went forth in a different direction upon his divine mission.
This was true consultation. This was spiritual consultation and not the mere voicing of personal views in parliamentary opposition and debate.
(`Abdu’l-Baha: Promulgation of Universal Peace, p. 73)