Yes Isis was an Egyptian goddess, but in the 1st, 2nd and 3rd centuries she was worshipped in many countries of the empire, especially in Rome. There was a temple of Isis in Pompeii. There was a temple of Isis in Rome, near the Pantheon. At the end of the Metamorphoses of Apuleius, a 2nd c. latin North African author, there is an apparition of Isis who says she has many names, that all other goddesses should be assimilated with herself... " I, mother of all Nature and mistress of the elements, first-born of the ages and greatest of powers divine, queen of the dead, and queen of the immortals, all gods and goddesses in a single form; who with a gesture commands heaven's glittering summit, the wholesome ocean breezes, the underworld's mournful silence; whose sole divinity is worshipped in differing forms, with varying rites, under many names, by all the world. There, at Pessinus, the Phrygians, first-born of men, call me Cybele, Mother of the Gods; in Attica, a people sprung from their own soil name me Cecropian Minerva; in sea-girt Cyprus I am Paphian Venus; Dictynna-Diana to the Cretan archers; Stygian Proserpine to the three-tongued Sicilians; at Eleusis, ancient Ceres; Juno to some, to others Bellona, Hecate, Rhamnusia; while the races of both Ethiopias, first to be lit at dawn by the risen Sun's divine rays, and the Egyptians too, deep in arcane lore, worship me with my own rites, and call me by my true name, royal Isis." For many people Isis was the sole goddess. You shouldn't say God (the god worshipped in churches, in mosques) is a Jewish god? Same for Isis...