Or, to choose another analogy, you trust that your car will start in the morning because you bought the car new and it works and the people who built the truck have almost any given reason to do a good job.
It's when the car shifts in a wonky way that you might begin to wonder if the transmission is working the way it's supposed to. You might find that the brakes don't seem to work as they should and you have a few near misses or a ding or two. Or you might discover that turning is rough or that the power to weight ratio suffers in cold weather or hot weather. Eventually the car fails but if a lot of these little failures happen within a few months of buying a new car you've got a clunker, or a car that was made well, perhaps, but with very bad parts.
The bottom line is that you don't decide the car is busted on the basis of just one drive the way this works. It how it gets you from point A to point B day in and day out. You can't ignore that some of the trouble is that you're a good or bad driver and external circumstances come into play. But there comes a point when you recognize that the car is a good car, perhaps, that needs repairs and that even the worst-made car will not fail you without a number of smaller things accumulating along the way.
In other words, trust is built up slowly and lost slowly ... but that feeling of ultimate and shocking betrayal still seems like it just suddenly HAPPENS. So efforts to assess and refine and cultivate trust are necessary. There's a wonderfully amusing sequence in the comic book and the film Persepolis where Marjane looks back on all the things that seemed wonderful about her beau ... right up until she caught him boffing another woman, and sees in all the things endearing only things that were disgusting. Her perspective changed because of the emotional shock of betrayal and yet in the comic book she's circumspect enough to recognize that everything was there to be seen but she was so desperate to love and be loved she didn't see what was staring her in the face and didn't realize what spectacular expecations and hopes she hung upon a young man who was no more stable nor mature than she. The shock of the betrayal rests on cumulative effects, of hints and grievances overlooked in the hope that what was seen was not what was real.
In Scripture the great betrayal is that of Judas. Judas betrayed Jesus with a kiss, but a lot of little betrayals that escaped the notice of everyone but Jesus came and went to get to that point. But it makes sense that it's shocking once it happens and the apostles who share the betrayal don't beat around the bush. Matthew tips us off in chapter 10 that Jesus will be betrayed. Mark doesn't even wait that long and mentions it by chapter 3. Luke mentions Jesus' revelation that He will be betrayed but doesn't reveal who the betrayer is until quite a bit later. Luke is a more careful dramatist, perhaps, not wanting to give things away too quickly. John gets things out of the way fairly early, like the other Gospel authors but provides a bit more insight into Judas' character. It was only John who had a closer perspective on Judas' pre-betrayal betrayals, and it is Luke who artfully postpones the revelation of the betrayer and helps convey the sense of shock that the other Gospel authors, all having closer apostolic attestation, simply get over with quickly in the interests of getting to Jesus' teaching (or so it would seem).
There was once a neighborhood dog that was rabid and would attack passers by. The owner of the dog would dispute the reputation of the dog to everyone, saying that the dog was just defending himself and defending his territory and that if people would only just UNDERSTAND the dog's motives and what he was REALLY trying to do that it would all make sense. The dog didn't attack anyone who didn't deserve it, more or less.
Then one day the dog wanted more food than the master thought he deserved and bit the dog's owner. The owner said, "Damn! That hurt. You're a bad dog!" But since the dog had been allowed to harass and even bite passers by for years could the owner really suddenly blame the dog for being exactly what the owner let the dog be? Why was it only unjust for the dog to attack and harass his master when his attacks on others had gone by not only without complaint but with defenses? The owner trusted that the dog would NEVER bite him. The truth was simply that the evidence of the dog's cantankerous nature had always been there but the man simply ignored what was before him because so long as the dog was attacking other people and not him the fault was probably that of those who got bitten.
So at question here is whether or not we can meaningfully parse blame now. We can, to be sure, but in a way it is an exercise that is merely Sissyphean. The dog is to blame for choosing to bite even if by nature and permission of his master. Conversely, the master is guilty of not defending those attacked by the dog befire and, while clearly not deserving to get bit by his own dog any more than anyone else, bears culpability. It's sad, but true. The neighbors who wanted the dog's aberrant behavior challenged got ignored and what can they do now that the dog has bitten pretty much everyone in the neighborhood? To say that the dog's behavior is a problem is too late, by now the dog's conduct has become the responsibility of all, in an admittedly broad manner of speaking. The neighbors who decided to not go near the dog turned out to be smarter than all the people who thought the dog would not bite them. By way of caveat, perhaps I should say I've always liked cats better. :)
The dog whose bark was worse than his bite probably didn't invent that saying. It was probably coined by a dog whose bite was much worse than his bark, and whose bark was still pretty nasty.
Aphorisms are peculiar things. I once heard an explanation that to be a peace-maker sometimes only happens when you destroy all your enemies so that there can finally be peace. Yeah, blessed are those peace-makers, eh? An interpretation so spectacularly at odds with nearly two millenia of Christian tradition might go unnoticed by people who heard this interpretation until it were actually applied! Not exactly dipping into the same well that Matthew Henry and Wesley drew from (to pick the most obvious choices of standard free on-line commentary by venerable commentators of the past).
I grant that it is, in the Apocalypse, totally true, but bringing forward that definition of peace-making that is reserved only for Christ is what someone might somewhat laconically call an over-realized eschatology.