In recent years, Protestant theology—particularly of the Reformed and evangelical variety—has shown an increased interest in historical retrieval. Various theologians have engaged in the work of mining the Great Tradition of Christianity in order to resource contemporary theology with wisdom from the past. Presupposed in this work of retrieval is a claim that is by no means a foregone conclusion for Roman Catholic and Eastern Orthodox theologians: the notion that Protestants also lay claim to the Great Tradition of the ‘one, holy, catholic, and apostolic church.’ Protestant theologians working on retrieval believe they are drawing from their own heritage, not the heritage of another. While it may appear counterintuitive to do so, this paper seeks to defend this notion by drawing together three terms commonly considered disparate: Christian Platonism, Reformed soteriology, and Baptist sacramentalism. It disputes two popular insistences: first, that Reformed soteriology depends on a nominalism that contradicts the realism of the Christian-Platonic metaphysical tradition; and second, that the Baptist view of baptism amounts to mere symbolism (and thus depends on nominalism in another sense). This paper therefore argues not only that Reformed evangelicals, broadly speaking, lay rightful claim to the Great Tradition (and specifically, its metaphysics), but also that Baptists in particular share this heritage.