He was born at Brilon, in Westphalia, studied general literature at Paderborn, and theology at Bonn, Tübingen and Munich.
In the controversies on the infallibility of the Pope, Reusch belonged to Döllinger's party, and he and his colleagues Bernhard Josef Hilgers, Franz Peter Knoodt and Joseph Langen were interdicted by the Archbishop of Cologne in 1871 from pursuing their courses of lectures.
In 1874 and 1875 he was the official reporter of the memorable Reunion Conferences held at Bonn in those years and attended by many distinguished theologians of the Oriental and Anglican communions.
Among his many works were contributions to the Revue internationale de theologie, a review started at Bern at the instance of the Old Catholic Congress at Lucerne.
He wrote also works on the Old Testament; a pamphlet on Die Deutschen Bischöfe und der Aberglaube; and another on the falsifications to be found in the treatise of Aquinas against the Greeks; as well as essays on the history of the Society of Jesus, and a book of prayers.
He died in Bonn leaving behind him in manuscript a collection of letters to Bunsen about Roman cardinals and prelates, which has since been published.