Thanks for your response.
Reading the OP, the author is simply presenting his personal POV, albeit very influenced by being a Baha’i.
The Baha’is rightly or wrongly believe Bahá’u’lláh to be the latest Manifestation from God and has therefore brought a Revelation from God in the same manner as Moses, Christ, and Muhammad. We then go on to claim that Buddha and Krishna were also Manifestations from God. That’s an extremely challenging and ‘out there’ perspective for adherents of all those Religions. Instead of the Baha’is saying you guys are wrong, we say you guys are right but you have misunderstood your own religion. We're bound to ruffle more than a few feathers.
In regards Islam, Baha’is believe the Holy Qur’an to be the authenticated respository of the Word of God. Although we hold the Gospels as being authentic, unlike the Qur’an they are not wholly authentic. We believe Muhammad to be the Messenger of God He claims to be. However, we are not Muslims but Baha’is. Why? We believe Bahá’u’lláh has Revealed the latest Message from God to humanity. Muslims of course not only cry foul, but heretic, apostate and death to the Baha'is as of course they believe Muhammad words 'seal of the prophets' to mean that the flow of God's grace through Divine revelation has been forever stilled.
With that said, I believe Muhammad’s words about Christ need to be considered in the context of God’s Revelation to the pagan Arabian tribes. They did not have great knowledge about either Christianity or Judaism. Muhammad affirmed it wasn’t enough to believe in Him but in all the prophets who had gone before with special emphasis on Moses and Jesus who had brought the Torah and Gospel. However, Muhammad is clear as to how the Christians have erred in their understanding of God. The key areas of concern are the Divinity of Christ, the sonship of Christ, and the trinity. It’s is no coincidence that these beliefs are enshrined in the Nicene Creed composed during the fourth century, just a few centuries before the rise of Islam.
Unfortunately this led to the false belief (Baha’i perspective) that the Gospels were corrupted. Muhammad never said they were but the Ulama have inferred they were. So Islamic theology has developed under the false premise about the gospels that say much more about Christ than the Qur’an. Some modern Islamic scholars are playing catch-up and redefining what Muhammad said with due consideration to the Gospels. Many remain locked in the past.
Bahá’u’lláh however highlighted the problem with Islamic interpretation in the 19th century.
We have also heard a number of the foolish of the earth assert that the genuine text of the heavenly Gospel doth not exist amongst the Christians, that it hath ascended unto heaven. How grievously they have erred! How oblivious of the fact that such a statement imputeth the gravest injustice and tyranny to a gracious and loving Providence! How could God, when once the Day-star of the beauty of Jesus had disappeared from the sight of His people, and ascended unto the fourth heaven, cause His holy Book, His most great testimony amongst His creatures, to disappear also? What would be left to that people to cling to from the setting of the day-star of Jesus until the rise of the sun of the Muḥammadan Dispensation? What law could be their stay and guide? How could such people be made the victims of the avenging wrath of God, the omnipotent Avenger? How could they be afflicted with the scourge of chastisement by the heavenly King? Above all, how could the flow of the grace of the All-Bountiful be stayed? How could the ocean of His tender mercies be stilled? We take refuge with God, from that which His creatures have fancied about Him! Exalted is He above their comprehension!
Bahá'í Reference Library - The Kitáb-i-Íqán, Pages 81-93