All of the above.
A long time ago a dear friend of mine argued with me about lies. We nearly stopped talking because she thought that there is a time a lie can be acceptable. We talked again about the topic and she sees my point.
A person that will lie about one thing cannot be trusted about anything.
Every word from that person becomes suspect. "I only lied because I needed the money!" Yes- and how do we know you don't have an equally compelling excuse for lying to us now?
My friend has said she agrees with me at least most of the time now, since dealing with dishonest people for a few years. She's learned that there is no way to tell "little dishonest" from "fucking liar". So any lie must be suspect as the worst case - if they will lie about unimportant things chances are they are MORE likely to lie about important things - like if they are single.
I'm sorry she had to suffer a lot to learn. I'm even more sorry that others will suffer more because telling lies has become a social norm.
Sometimes it is good to be a sheltered little nut.
Bye for now.