>I'm a good part of the way through the Old Testament and am currently wondering why people feel religiously disposed after reading it.
I wouldn't say I became a full believer after reading the OT, but I definitely saw the beauty of the religion after going through most of it.
Largely because of the reasons you listed (that it stresses "familial loyalty, trust, forgiveness, and the importance of bonds"), the OT rises above as a great work. Not only that, but it has some legit characterization and a lot of thought was put into it.
IMO, it's less about turning you into a believer than it is about being a good introduction to their religious history and guidelines. That, in turn, will get you to perhaps look into the community sides of things, which will help you look into deeper meanings and alternative explanations for things in the OT, which will in turn help you believe.
But, most importantly, I like the OT because it kind of presumes that some of its readers/listeners wouldn't buy it. So, from the perspective of a non-believer, it did a good job of considering the benefits, the weaknesses, and the utter totality of having a God -- the Job kind of God, or the kind of God that fucked over Saul, and yet the God who nonetheless fought for the Jews again and again.
It's interesting; it's contradictory; and it's aware of itself, aware of its seeming ridiculousness, knowing that that's what it means to believe.
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I've never really liked the NT because it basically hits your over head and shames you into believing. "What, you don't believe in God? You don't believe in Jesus? Maybe you're just too rotten or too stupid..."
There's obviously a bit more nuance, but starting their New Testament with the Gospels was effectively their way of saying just that, since those Gospels lack the characterization of almost every OT and Apocryphal book.