Hugh Schonfield wrote in The History of Jewish Christianity:
The initiative was taken by the Hebrew Christian Alliance of America (founded in 1915). They suggested as a preliminary measure the convening of an International Hebrew Christian Conference. Mark John Levy crossed the Atlantic several times in the interests of the proposal. After protracted discussion and correspondence with the British Hebrew Christian Alliance (founded in 1866), a joint letter of invitation was sent to Hebrew Christians in all parts of the world. In its way, the letter was as significant as that famous epistle to the Gentile believers issued by the first Council of Jerusalem (Acts 15). It was dated for March, 1925 [exact date not given], and read as follows:
Dear brethren in the Lord Jesus our Messiah,
We, members of the Hebrew Christian Alliances of Great Britain and America send you hearty greetings. 
Since the days of the Apostles, Hebrew Christians have been scattered units in the diaspora, ostracized by our unbelieving brethren and lost among the nations. We believe, however, that the times of the Gentiles are being fulfilled and that the God of our fathers, according to His gracious promise, is about to restore Israel to her ancient heritage. We also believe that as Hebrew Christians, though a remnant weak and small we have a share in the building up of “the Tabernacle of David that is fallen down.”
We deem it an opportune time to meet and confer together, seeking Divine guidance by prayer and the Word of God.
We have therefore decided to hold D.V. an INTERNATIONAL HEBREW CHRISTIAN CONFERENCE in London. England, this year from Saturday, September 5 to Saturday, September 12, and to this we heartily invite you.
Many living in distant parts, maybe prevented from joining us by the heavy travelling expenses, but it is hoped that the Hebrew Christians of various towns or countries may be willing to raise the means and send delegates to represent them at the Conference; they will then be able to take back a report of the proceedings.
The Hebrew Christian Alliance of London will, however, during the period of the Conference. September 5-12, give themselves the pleasure of providing hospitality to all delegates who will have registered beforehand and will have received cards and badges. To such delegates full particulars, together with the  programme, will be sent in due course.
With cordial greetings.
On behalf of the Hebrew Christian Alliances of Great Britain and America,
Yours in our Common Master,
Samuel Schor, President
J.J. Lowe, Treasurer
Bendor Samuel, Hon. Secretary
The Conference duly met at the Wilson Memorial Hall, Islington, the only shadow over the proceedings being the absence of The Rev. Samuel Schor, owing to illness. Rarely can there have been witnessed such a fervent gathering. Eighteen countries were represented. On the rostrum are proudly displayed die Union Jack and the Jewish Flag, while between them hung the Jewish Christian motto, “How good and how pleasant it is for brethren to dwell together in unity.”
It was on September 8 that the historic resolution was carried unanimously:
That we Hebrew Christians from different parts of the world standing for the Evangelical Faith now met in Conference, re-affirm our living faith in the Lord Jesus Christ, as our Messiah, and our oneness in Him; and do hereby declare that we now form ourselves into an INTERNATIONAL HEBREW CHRISTIAN ALLIANCE.
Prayer: Thank you Lord for the formation of the International Hebrew Christian Alliance in 1925, a landmark in the history of Jewish believers in Yeshua. The Messianic Jewish movement worldwide owes a debt of gratitude to these pioneers, and builds on their legacy. May we too continue in our day to live our lives with integrity and faith, building and renewing the institutions they foresaw, and continue to bring healing, reconciliation and proclamation to our people Israel and the wider church. In Yeshua’s name we pray. Amen.