Final answer:
The sculptures in Romanesque churches were indeed used to educate and instruct the largely illiterate audience of the time, functioning as 'books in marble' and being a critical tool for the churches to guide the faithful through visual storytelling.
Step-by-step explanation:
The statement that sculpture in Romanesque churches, especially on the pilgrimage routes, served as "books in marble" to impress, educate, and instruct a largely illiterate audience is true. This period's art was didactic, with sculptures on the facades and portals of churches like Chartres Cathedral telling biblical stories and conveying religious truth to all viewers, regardless of their literacy. Among the most important sculptural forms of this era were the tympanum and historiated capitals, which, along with illustrated manuscripts, assisted in the religious education of the public. Thus, the visual arts became a method for the church to guide the faithful, to instruct and move them, making these artworks essential tools for disseminating complex theological concepts through vivid and accessible storytelling.