A friend of mine was a student of the American Civil War. On several occasions he expressed dismay at the fact that both sides in that conflict could worship the same God and look to the same Bible to support their cause. Northerners took the scriptures to condemn slavery, while the southern church found biblical evidence to justify it. Given the history of warfare inspired between various factions of Christianity, our own national experience is not that surprising. Of course, the literal brother against brother aspect of a civil war makes the religious aspect all the more poignant and ironic.
Throughout its history, the church, its leaders, and members have struggled to define and communicate what I would call a consistent theology of God's nature, His purpose, and His operation in relationship to humanity. By consistent, I mean an understanding of these things which is supported by the entirety of the Bible from Genesis to Revelation. In my experience, any time one examines anyone's theology in relationship to the entire Bible there are numerous passages which seem contradictory. Again in my observation, each proposed defense of a consistent theology revolves around this need to resolve what appear to be basic inconsistencies.
The defenders of various theological positions use a variety of explanations for what they see as only supposed inconsistencies. A common one is to simply define some other Bible passages as axiomatic and therefore unquestionable. Then, any other passages cannot be contradictory, only misunderstood. Thus the proponents must manipulate the unsupportive words to eliminate or minimize any apparent contradiction. Countless creative counterarguments have been advanced in just this way.
If one reads the commentaries, you cannot fail to notice that often the writers skim quickly and lightly over passages which appear troublesome to the writer's theology, making little or no note of them. Thus we see another strategy for advancing a "consistent" theology: simply ignore the parts of the Bible that don't serve that theological position. This particular tactic is a part of everyone's Bible based theology to some degree, so it is basically inevitable.
Finally, the very poetic nature of much of the Bible absolutely invites fanciful interpretations. The use of metaphors, allegories, parables, hyperbole, and prophecy open the door to as many personal understandings of the scriptures as there are students. Thus, again we should not be surprised at the diversity of opinion we see concerning the Bible.
If there is any reason to be surprised at the use of the Bible, it is because anyone would ever insist that they have an irrefutable, consistent theology drawn from its pages. We have the evidence to the contrary in bother history and personal experience.
So take your pick. Our forefathers did, and we must do the same.