[1]: 8  In his teens he intended to emigrate to America with a brother-in-law but a theft compelled him to give his brother his share of money to continue the journey while he remained in Hull England, where he first encountered Christianity.

[1]: 9 Through a mutual acquaintance, Baron was introduced to Rev John Wilkinson of the Mildmay Mission to the Jews, who invited him to a Bible study session in April 1877, at which he received a copy of the New Testament.

[4] In a matter of years the HCTI published about 38 Christian texts in Hebrew, Yiddish, German, English, Russian, Hungarian, French and Italian, with particular missionary emphasis among women and children.

In the aftermath of World War I significant evangelism was conducted in Russia and Eastern Europe, where polemics were exchanged with prominent community rabbis.

[1]: 44-48  Baron's chief strategy was to present Jesus as the fulfilment of Messianic prophecy[2]: 378  Focus was placed upon areas with particularly large concentrations of Jewish people, like Russia, Hungary, Transylvania and Germany.

Some missions activity in Eastern Europe was transferred to Palestine, and cooperation was sought with other Christian organisations working there to take advantage of the influx of Jewish immigrants in the wake of the Balfour Declaration.

[1]: 14  Much of his theological formation was influenced by Free Church of Scotland ministers like Andrew Bonar, whose biography of Robert Murray M'Cheyne he referred to as "one of the first Christian books that I read.

"[1]: 21–22  From Bonar, who was associated with famous American preacher Dwight L. Moody, Baron adopted a revivalist perspective and dispensational premillennial eschatology.

[1]: 67  A key part of Baron's theology that shaped his methodology was his belief that the law as interpreted by Rabbis was stifling people under what he called "Jewish popery", and that an understanding of Jesus as fulfillment of the sacrificial system brought spiritual renewal.