Original: Before the conquest by Arabian Muslims reached Lebanon, the Lebanese people including those who would become Muslim and the majority who would remain Christian, spoke a dialect of Aramaic.
Simplified: Before the conquest by Arabian Muslims reached Lebanon, which resulted in the Arabization of both those who would become Islamized and those that would remain non-Islamized, the Lebanese people, including Maronites, spoke a dialect of Aramaic, but have been Arabic-speaking since at least the 15th century.