I've read that large portions of scripture are POLEMICS, which means critical responses. If you are clueless, read the sermon on the mount, from the beatitudes to the lord's prayer, all polemics on what had been done wrong - "you've heard ... but I say unto you ..." Likewise, all pauline epistles are his counselling to various issues in each of these early churches. Therefore, correct interpretation requires understanding of the original issues in the original historical context. If you don't know anything about the historical context, neither will you understand the response.
To make a perhaps inappropriate example, you study american civil war, canonical documents tell you that it's all about slavery and racism; then there's a new research providing a new view, that the primary cause is dispute over western territory and economic policy, the north wanted to build factories, the south plantations; the north wanted strong currency and high tariff for local industry development, the south weak currency and low tariff for exports and imports with europe. The war erupted at the point when these two economic models could no longer coexist. But if you don't know anything about the civil war, if you don't even know such a civil war ever existed, you apply this view on some other wars in other historical eras, then you'll surely get lost.
