Why do I feel like I was mentally stronger when back then when I was reading the Bible?

Reminds me of the guy from “The Wave” who was a social shut-out before the experiment, became empowered, confident, and certain because of the experiment, and was completely devastated when it all fell apart.
I would say that a sense of absolute certainty, even if it is completely fake, is a lot more empowering mentally than constant doubt, especially to someone who for the most part of his life knew nothing but this fake certainty.

Whoa, is this going to be one of those days? I’m actually in agreement with @ragingloli here.

When you were reading – and presumably following – the Bible, then you had, as you put it, a “direction” in life. You had a stable datum, the Bible itself, against which you could align the rest of the world. The thing about a stable datum is that it doesn’t matter whether it is “true” or not; if you can consider it stable enough, then it’s a rock that you can use to anchor your view of everything else in the world: in alignment with the Bible or not, and act accordingly.

The fact that hundreds of millions of people also do the same, and openly, makes for additional confirmation of your stance.

Science is another excellent – some would say (and I always say) a better – stable datum, but the problem for anyone relying on “science” these days is that it’s not so stable! The Bible doesn’t often change. (It does change, with every edition and every translation, but those are infrequent.) Science changes daily, which means that your view of the world can alter in fundamental ways practically overnight. And yes, you do have to “fact check the world” on many issues.

But I would say that a healthy curiosity about the world, and a willingness to adapt beliefs to fit observed facts, actually makes you mentally stronger. More limber, in any case. If you’re going to rely on science (unless you restrict your view of “science” to Newtonian physics, for example), then you will have to adopt a somewhat humble and open-minded approach to knowledge, because what you think you know today may be disproven and all wrong tomorrow, and you have to be willing to live with that uncertainty.

There’s a lot more to mind than rational thought. The intellect is very important, but its range of operation is restricted to the known and knowable. The worldview afforded by the rational mind is incomplete, but according to that worldview the incompleteness is just due to a lack of information. Rationality takes for granted that given enough time, resources and data, everything could potentially be intellectually accounted for.

But there is an aspect of mind that takes a very different and complementary perspective. It’s not concerned with knowing. You could say that it’s the mind of not-knowing, in that it contemplates reality without breaking it up into knowable chunks, instead leaving it whole and unprocessed. The perspective that this function of mind yields can’t be formulated as a compendium of facts without losing the truth of it.

These aspects of mind are constantly working seamlessly together to create our experience. We can look at them separately, as I’ve just done, but that’s an artificial exercise. It’s easy to be aware of the workings of the rational aspect of mind, because it is overtly conscious. Since it deals in the knowable, its conclusions can be discussed and explained and justified. The rational mind starts to look like the sole custodian of the “real”.

The other aspect of mind, the holistic function, is every bit as vital, but it operates quietly, at a less conscious level. Without it, though, consciousness wouldn’t even be possible. Its perspective informs, stabilizes and balances a healthy mental life (which I assume is what you mean by “mental strength”). Leave it out of consideration by denying all but the rational, and an unease may settle in. That unease is the persistent clamor of the holistic aspect for recognition. It feels like a nagging intuition that we’re overlooking something important.

I have my issues with the Bible, which is why I set it aside long ago, but I do recognize that it speaks to this nagging intuition. It says, in effect, “that ‘something missing’ is God”, and then purports to inform us about God. This vaguely scratches that itch to bring this holistic mind out of the closet. I happen to think that this approach can only go so far in scratching the itch; at least that was my experience.

Keep reading and studying your Bible.

@pleiades I can only guestimate based on my personal experiences. I always feel mentally, emotionally and spiritually stronger when I draw closer to God.

If you (like me) were raised thinking it was the only way to truly be alive and whole and ‘good’, I’m not sure that will ever change, although I tried my best to divurge from it for years of my life. Explaining it to non-believers is very difficult, but I hope you understand.

Some people truly think religion is a mental illness, sadly.

Believing in something ardently is very comforting and strengthening. Nothing can happen to you that is other than the way it should be. You gain a sense of certainty that you don’t have to bend before uncertainty. You will be taken care of in any case. Certitude is an armament against failure.

Yes, a feeling of certainty will make people feel better, no matter what it is about (or if it’s actually true).