There is vast amount of evidence from the Church Fathers that, there was a certain sect in Arabia that believed the Trinity consisted of: “Father, the Son and Virgin Mary.”
1. George Sale
“This notion of the divinity of the virgin Mary was also believed by some at the council of Nice, who said there two gods besides the Father, viz., Christ and the Virgin Mary, and were thence named Mariamites. Others imagined her to be exempt from humanity, and deified; which goes but little beyond the Popish superstition in calling her the compliment of the Trinity, as if it were imperfect with her. This foolish imagination is justly condemned in the Koran as idolatrous….” 2. Reverend Gilbert Reid D.D.
“As to Christianity as it was represented in Arabia, it was not a clear untarnished theism, but tritheism. The Heavenly Father, Mary the mother of God and Jesus their son, were WORSHIPPED as three Gods, and their images appeared in the churches along with the images of other saints. Christianity as taught by Christ had lost its identity in the formalism and errors of the church of Arabia. Still more the truths pro-claimed by God through all the ages had been lost sight amid the vain imaginings of men’s hearts. The only God of, an omnipresent spirit, without form or body. The reformation of Mohammed was thus a return to the first and second commandment of the Prophet Moses, which Jesus himself had taught.” 3. Washington Irving
“The Mariamites, or worshippers of Mary, regarded the Trinity as consisting of God the Father, God the Son, and God the Virgin Mary. The Collydrians were a sect of Arabian Christians, composed chiefly of females. They worshipped the Virgin Mary as possessed of divinity…..” 4. English theologian Theophilus Lindsey writes:
“The followers of Christ had been for some ages quarrelling and destroying each other in their heat’s and disputes, not concerning the Supreme Father of all, to whom they paid little attention; but about the nature of Christ. And of the Holy Spirit, and many other objects of worship, which they invented. (t) The notion of the divinity of the Virgin Mary was believed by some even at the council of Nice: who said there were two gods besides the Father, viz. Christ and the Virgin Mary, and were thence names Mariamites. Others imagined her to be exempt from humanity, and deified: which goes but little beyond the Popish superstition, in calling her the complement of the Trinity….” 5. William Cook Taylor
“In Arabia itself some of the worst heresies were propagated: the chief of these were the heresies of the Ebonites, the Nazareans, and the Collydrians, the last of which derived its name from the collyris, or twisted cake offered by them to the Virgin Mary, whom they worshipped as a deity. It is known to all readers of ecclesiastical history that a sect called Mariamites exalted the Virgin to a participation in the Godhead, and that writers of the Romish Church have named her the ‘complement of the Trinity.’….” 6. John Holmes
“….Jacobites, so called from Jacobus, Bishop of Edessa in Syria, and whose doctrine, directly contrary to that of the Nestorians in one point, denied the double nature of Christ in his state of incarnation: Mariamites, so called because they worshipped the Virgin Mary, and regarded her as, along with the Father, and the Son one of the persons of the Divine Trinity…. “7. John Henry Blunt D.D. :
“In Accordance with which are the statements of certain writers, logically in agreement with the worship they advocate, that St. Mary has been assumed into the Trinity, so as to make it a quaternity, that Mary is the ‘compliment of the Trinity.’” 8. Allan Freer
Nestorians, so called from their founder, Nestorius, Bishop of Constantinople and whose heresy consisted in a recondite distinction between Jesus the man, and Christ the God-man; Jacobites, so-called from Jacobus, Bishop of Edessa in Syria, and whose doctrine directly contrary to that of the Nestorians in one point, denied the double nature of Christ in his state of incarnation: Mariamites, so-called because they worshipped the virgin Mary, and regarded her as, along with the Father and the Son, One of the persons of the divine Trinity: and collydrians, a sect guilty of similar heresy, and deriving their name from their practice of offering to the virgin Mary a particular kind of cake, called Collyris.9. John William Draper
In the east, in consequence of the policy of the court of Constantinople, the Church had been torn in pieces by contentions and schisms. Among a countless host of disputants may be mentioned Arians, Basilidians, Carpocritains, Collydrians, Eutychians, Gnostics, Jacobites, Marcionites, Marionites, Nestorians, Sabellians, Vallentians. Of these the ; the Collydrians worshipped the Virgin as a divinity, offering her sacrifices of cakes…. We can see from all the references quoted, that Mary was indeed believed to be part of the Trinity, by certain Christian sects of Arabia.