What is this "Messianic Jew". In my oppinion this doesn't exist. Because for the Christians like me, who follow the teachings of Johannis Calvin, is the whole ceremonial law abrogated. The moral law is not abrogated, but it condemns us no longer. The Judaism is different from the Christian believe.
G-d gave the Jews at Mount Sinai his laws and this law is valid up to now for them. This so called messianic Jews should tell the truth about their believe.
I think they want to win new members of their "christian" group, but not in a straight way, but in a mendacious way.
For my as a christian, muslimes pray to the moongod al-ilah, who changed its name in the preislamic time to Allah. I can proof this, because Mohammeds father called Abdallah. The name of the moongod is part of his name. You can read this in Ibn Isaqs book: "The life of the prophet". This book is part of the sunna of the chiefmuslime Mohammed. The biographic part of the sunna is called sira. Every muslime must believe in this or he is no muslime.
Allah has three doughters, for which we know the names and a lot of more unnamed. In the pagan cult in Mekka all stars are children of the moongod Allah and the goddess of the sun.
The name of the tree goddesses, which are the children of Allah are Al-Uzza, Al-Lat and Manat. Al-uzza was the goddess of the Morning-Star. We know this star as Venus.
There are serious proofs, that in the first time of islam Mohammed has allowed his followers to pray to this three goddesses. There are the Satanic Verses. Later Mohammed has told his murdermuslimes, that the devil had bewitched him and he forbid the cult of this three goddesses.
Now when we know this, we can shurly said that something is wrong with this "Messianic Jews"