In my opinion sadly often people believe before they understand and 2+5 =5.

A case in point would be the appalling acts done in the name of God

Whether believing implies understanding may be controversial, but it is clear that understanding does not imply believing.

You are correct, one can understand the dogma of a religion without believing in it, but one can believe in something without understanding, take the atom bomb most people believe and know its awesome power with no understanding of how it works

...for truth is a property of sentences. ...

Since we cannot believe something without understanding it, it follows that understanding precedes belief.

No. True love is made of a good wife and lots of pillow talk.

I completely disagree.

On exactly what do you base your idea that "we cannot believe in something without understanding it"?

-ITL-

Shlomo, I agree with you, absolutely, that true love is better than any sort of property of sentences.

Responding more seriously, we must distinguish between "true" and "truth" and also acknowledge that the meaning of word is dependent upon its context.

Generally, we say that something is the "truth" is this something is a sentence that is the case. The sentence has the property of accurately describing the "world" or "that which is the case." We are assuming there is something outside of our language that our language refers to. In a practical sense, I agree with this assumption. But in a logical sense, this world exists conceptually only in our descriptions of said world.

We call a description true if it makes sense next to our most cherished descriptions. Fred tells Joe that he has seen a ghost. But Joe doesn't "believe" in ghosts. For Joe, "there is no such as ghost" is a cherished description, and for that reason incompatible with Fred's description of an experience. So Joe offers Fred a redescription of Fred's experience. "You were hallucinating."

There's a certain amount of prejudice on both sides, I think. And for that matter a certain amount of prejudice in all humans. All science (knowledge) is conjecture. I describe it as good enough, but never absolute and perfect. Always amenable to editing in the face of experience.

This view is something I assimilated from Rorty, Nietzsche, etc. I'm not nearly as original as I would like to be.

You say that "we know more today, etc." I want to call attention to the fact that you say "we know." This "we" is a reference to consensus. And consensus is the foundation of truth, for truth is a property of sentences. It was Rorty, especially, who persuaded me to view truth this way.

The world is full of disagreement. Both sides present their reasons. Right now, even, we are debating the nature of truth. And yet both "truth" and "nature" are words that evolved historically, from metaphorical roots. Logos is slimy. I identify very much with the linguistic turn in philosophy. I cannot respect any epistemology that ignores an investigation of what words are, for philosophy is made of words.

I'm quite fond of formal logic and mathematics and even have experience programming computers. I came to philosophy with left-brain expectations. It was my passion for epistemology that led me to see rhetoric and not logic as the foundation of philosophy. You could say that I abandoned a mechanical view for an organic view. I suspect that Wittgenstein underwent a similar transformation. I think we need to look at man more holistically, and ask ourselves if there really is a will to truth or if truth is just a means. No doubt some make an idol of Truth, but this itself is to act in a mythological way.
Man wants a mission, a virtue to identify with. For some this mission is certainty. For others creativity. For some it's not a mental virtue at all, but something physical..And then some pride themselves on money. My epistemology is based on motive and medium. Why do we hold opinions and what are these opinions made of?

"All the worlds a stage and all the men and women merely players.." One could consider Shakespeare and Tristan Tzara philosophers.

And I gladly confess that my knowledge is provisional.

But to say that we are mistaken is to say that we are mistaken in relation to something, a something I am skeptical about. In a practical sense, the "mirror of nature" paradigm is great, quite useful, one of mankind's best inventions. But perhaps for some purposes it is obsolete.

As I don't recognize any unchanging absolute, mistakeness itself is relative. You can think of it as a dynamic or pragmatic theory of truth. And I agree with Rorty that truth is a property of sentences. We use the word to praise a sentence that meshes well with the network of our beliefs and desires. One could even define a human mind as a network of beliefs and desires. But this is one possible description among many possible descriptions. We constantly redescribe "reality" to ourselves, and this includes redescribing ourselves. For one could describe self-and-reality as a self-re-describing knot.

"You can't catch me, I'm the gingerbread man."

What you "know" changed. Your present self can re-describe your past self's knowledge as a mistake. But at the time you called it knowledge. In the same way your future self may re-describe your present knowledge as a mistake.

1. How do you know that Quito is the capital of Ecuador. You may have evidence, but never absolute proof. 2. What do you know about Quito? Is it more than just the name of a city to you? This is not to deny its potential use as an opinion. It's that your "knowledge" consists of the relation of 3 abstractions: Quito, Ecuador, capital.

All that being said, the word "knowledge" is fine for everyday use. I just prefer the word "opinion" when it comes to philosophical matters.