Your story sound much like my grandfather's, Antonio Juan (Anton Hana) Dieck. There are a great many families in Mexico with the surnames of Moras (Morras, Mora) and Ayoub (Ayub). Belen is the Spanish translation of Bethlehem.
My records show a Jusef Kahlil Murra born to Negme Handal and Kahil Salameh Murra in 1884 in Bethlehem who married Giamile Gidi. I'm sure they were related to Juan (John, Hana)--cousins.