I say "the simplest and most rational" because there are other ways to interpret religious texts. Text study is not an exact science. If you want to, you can explain a text in a hundred different ways. The way you understand any document depends on your own expertise and your own bias. Even if you think your explanation is the correct one, it is difficult to prove it.
I mention "expertise" because it is only through labored study of primary source-texts that one can hope to find the truth. There is a science to text study, and it emerges the more you learn. If your mind is pattern-oriented, as mine is, it will figure things out on its own. Each type of text is its own world - you can be a total expert in Shulchan Arukh (a 16th century Jewish legal code), but that doesn't make you knowledgeable about the Hebrew Bible in any way.
If you are interested in understanding religious texts properly, keep an open mind. Discard any commentaries, beyond what is required to translate. Start with the Bible itself - it is the foundation on which everything else is built, and also remarkably interesting in its own right. I used to memorize Bible verses - I memorized about half of the Pentateuch as a student - and this is a powerful way of developing expertise. If you don't have time to memorize, simply read ten verses a day until you finish the book of Genesis. Don't get hung up on understanding every verse, as some verses will take you years to understand. Skip the geneologies if you wish, the main thing is to keep going and cover ground. As you do so, the Bible will offer up its secrets, and you will be amazed at what it actually says.