Who told us we could understand the Bible without theology and church history? 

‘The reformation Scripture principle always had the potential to be used in a way which did not simply critique the traditional teachings of the church but could also overthrow them wholesale. That this was the case is clear from the Socinians, whose radical scripture principle manifested itself in a major anti-metaphysical reconstruction even of those theological topics left substantially unchanged by the Reformers, such as the doctrine of the Trinity and that of the Incarnation. So radical was their critique that even hallowed patristic authors who both Catholics and Protestants had regarded, in their different way, as authoritative, were dismissed as Platonic perverters of true Christian theology. In place of either the teaching magisterium of the church, or the careful exegesis of scripture in critical relation to historical church traditions of exegesis and synthesis, the Socinians urged a literal and, over time, increasingly rational, biblicism which had little or no place for the collective wisdom of the church through the ages and which exhibited a strong anti-metaphysical tendency, lethal to classical Christian theism.’ Carl Trueman, John Owen: Reformed Catholic, Renaissance man, p.47