All Islam considers the Qur‘án the Word of God. In this sacred Book there are explicit texts which are not traditional, stating that Christ was the Word of God, that He was the Spirit of God, that Jesus Christ came into this world through the quickening breaths of the Holy Spirit and that Mary, His mother, was holy and sanctified. In the Qur‘án a whole chapter is devoted to the story of Jesus. It records that in the time of His youth He worshiped God in the temple at Jerusalem, that manna descended from heaven for His sustenance and that He uttered words immediately after His birth. In brief, in the Qur‘án there is eulogy and commendation of Christ such as you do not find in the Gospel. The Gospel does not record that the child Jesus spoke at birth or that God caused sustenance to descend from heaven for Him, but in the Qur‘án it is repeatedly stated that God sent down manna day by day as food for Him. Furthermore, it is significant and convincing that when Muhammad proclaimed His work and mission, His first objection to His own followers was, “Why have you not believed on Jesus Christ? Why have you not accepted the Gospel? Why have you not believed in Moses? Why have you not followed the precepts of the Old Testament? Why have you not understood the prophets of Israel? Why have you not believed in the disciples of Christ? The first duty incumbent upon ye, O Arabians, is to accept and believe in these. You must consider Moses as a Prophet. You must accept Jesus Christ as the Word of God. You must know the Old and the New Testaments as the Word of God. You must believe in Jesus Christ as the product of the Holy Spirit.” His people answered, “O Muhammad! We will become believers although our fathers and ancestors were not believers, and we are proud of them. Tell us what is going to become of them?” Muhammad replied, “I declare unto you that they occupy the lowest stratum of hell because they did not believe in Moses and Christ and because they did not accept the Bible; and although they are my own ancestors, yet they are in despair in hell.” This is an explicit text of the Qur‘án; it is not a story or tradition but from the Qur‘án itself, which is in the hands of the people. Therefore, it is evident that ignorance and misunderstanding have caused so much warfare and strife between Christians and Muslims. If both should investigate the underlying truth of their religious beliefs, the outcome would be unity and agreement; strife and bitterness would pass away forever and the world of humanity find peace and composure. Consider that there are two hundred and fifty million Christians and three hundred million Muslims. How much blood has flowed in their wars; how many nations have been destroyed; how many children have been made fatherless; how many fathers and mothers have mourned the loss of children and dear ones! All this has been due to prejudice, misunderstanding and imitations of ancestral beliefs without investigation of reality. If the Holy Books were rightly understood, none of this discord and distress would have existed, but love and fellowship would have prevailed instead. This is true with all the other religions as well. The conditions I have named will apply equally to all. The essential purpose of the religion of God is to establish unity among mankind. The divine Manifestations were Founders of the means of fellowship and love. They did not come to create discord, strife and hatred in the world. The religion of God is the cause of love, but if it is made to be the source of enmity and bloodshed, surely its absence is preferable to its existence; for then it becomes satanic, detrimental and an obstacle to the human world.
(‘Abdu’l-Bahá, The Promulgation of Universal Peace, p. 200-202)

From the standpoint of institutionalism Islam far surpasses true Christianity as we know it in the Gospels. There are infinitely more laws and institutions in the Qur‘án than in the Gospel. While the latter’s emphasis is mainly, not to say wholly, on individual and personal conduct, the Qur‘án stresses the importance of society. This social emphasis acquires added importance and significance in the Bahá’í Revelation. When carefully and impartially compared, the Qur‘án marks a definite advancement on the Gospel, from the standpoint of spiritual and humanitarian progress.
(Shoghi Effendi, Lights of Guidance, p. 495)

In the early ages of Islam the peoples of Europe acquired the sciences and arts of civilization from Islam as practiced by the inhabitants of Andalusia. A careful and thorough investigation of the historical record will establish the fact that the major part of the civilization of Europe is derived from Islam; for all the writings of Muslim scholars and divines and philosophers were gradually collected in Europe and were with the most painstaking care weighed and debated at academic gatherings and in the centers of learning, after which their valued contents would be put to use. Today, numerous copies of the works of Muslim scholars which are not to be found in Islamic countries, are available in the libraries of Europe. Furthermore, the laws and principles current in all European countries are derived to a considerable degree and indeed virtually in their entirety from the works on jurisprudence and the legal decision of Muslim theologians.
(‘Abdu’l-Bahá, The Secret of Divine Civilization, p. 89)

(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 5)

(Shoghi Effendi, Lights of Guidance, p. 494-495)

Muhammadanism is not only the last of the world religions, but are fuller Revelation than any one preceding it. The Qur‘án is not only more authoritative than any previous religious gospel, but it contains also much more ordinances, teachings and precepts, which taken together constitute a fuller Revelation of God’s purpose and law to mankind than Christianity, Judaism or any other previous Dispensation. This view is in complete accord with the Bahá’í philosophy of progressive revelation, and should be thoroughly accepted and taught by every loyal Christian Bahá’í.
(Shoghi Effendi, Lights of Guidance, p. 497)

The Bahá’í view on that subject is that the Dispensation of Muhammad, like all other Divine Dispensations, has been fore-ordained, and that as such forms and integral part of the Divine Plan for the spiritual, moral and social, development of mankind, It is not an isolated religious phenomenon, but is closely and historically related to the Dispensation of Christ, and those of the Báb and Bahá’u’lláh. It was intended by God to succeed Christianity, and it was therefore the duty of the Christians to accept it as firmly as they had adhered to the religion of Christ.
(Shoghi Effendi, Lights of Guidance, p. 495)

(Shoghi Effendi, God Passes By, p. 364)

The friends should uphold Islam as a revealed Religion in teaching the Cause.
(Shoghi Effendi, Lights of Guidance, p. 496)

There is so much misunderstanding about Islam in the West in general that you have to dispel. Your task is rather difficult and requires a good deal of erudition. Your chief task is to acquaint the friends with the pure teaching of the Prophet as recorded in the Qur‘án, and then to point out how these teachings have, throughout succeeding ages, influenced nay guided the course of human development. In other words you have to show the position and significance of Islam in the history of civilization.
(Shoghi Effendi, Lights of Guidance, p. 494)

We entertain no prejudice against Muhammad. Outwardly the Arabian nation was instrumental in overthrowing the Parsi dominion, the sovereignty of Persia. Therefore, the old Parsi nation manifested the utmost contempt toward the Arabs. But we deal justly and will never abandon the standard of fairness. The Arabians were in the utmost state of degradation. They were bloodthirsty and barbarous, so savage and degraded that the Arabian father often buried his own daughter alive. Consider: Could any barbarism be lower than this? The nation consisted of warring, hostile tribal peoples inhabiting the vast Arabian peninsula, and their business consisted in fighting and pillaging each other, making captive women and children, killing each other. Muhammad appeared among such a people. He educated and unified these barbarous tribes, put an end to their shedding of blood. Through His education they reached such a degree of civilization that they subdued and governed continents and nations. What a great civilization was established in Spain by the Muslims! What a marvelous civilization was founded in Morocco by the Moors! What a powerful caliphate or successorship was set up in Baghdad! How much Islam served and furthered the cause of science! Why then should we deny Muhammad? If we deny Him, we awaken enmity and hatred.
(‘Abdu’l-Bahá, The Promulgation of Universal Peace, p. 346-347)

(Shoghi Effendi, Lights of Guidance, p. 495)

(‘Abdu’l-Bahá, The Promulgation of Universal Peace, p. 201-202)