Complex sentence: Missionaries in Mesoamerica attempted to take already existing symbols and elements in the local indigenous religions and societies, and give them Christian meaning and symbolism; e.g., the Mesoamerican world tree, which they interpreted as a cross.
Split into simpler sentences: Missionaries in Mesoamerica attempted to take already existing symbols and elements in the local indigenous religions and societies, and give them Christian meaning and symbolism. E.g. The Mesoamerican world tree, which they interpreted as a cross.