OK, seeing that Cinlef don't post the versicles in question, I'll post a couple that I think can be interpreted to do what he is pointing.
Here is a versicle when Jesus was praying to God:
John 17:17For Jesus, the Word of God was the truth.
The origin and nature of the scripture:
2 Peter 1:20-21Here the scripture is describing how we have the scripture now, and the way we must study it.
Here is an example about how it was written:
Jeremiah 36:4OK. Now think. Did you have in your life an experience like this?:
Suppose that you are talking with your mother or a very close friend, and she/he says: "would I lie to you? I am telling you the truth".
Is that a valid thing for her/him to say? It depends entirely in the confidence that you have to that person. It depends on affections, how much you know the person, what kind of relationship you have, etc.
You can't say that to an stranger, you can't say that to someone that don't know you at all. If you try to validate what you are saying to an stranger with your own words, it would be "full circular logic", but if the two persons already know each other, it may be different.
When your mother says that, it is because she is trying to make you think about all she did for you and how much she loves you; so, if you are unsure if she may be laying to you on the situation, she is making you realize that with all she did for you in the past and all the love she has shown to you, it is quite unlikely that she is going to lie to you now, causing an damage.
It is entirely based in the quality of the relationship that you already have with the person.
So, may be that you already have been studing the scripture and you realized that it have something divine, but you are not certain about its origin, and you have been heard that it expresses thoughts of men with hight moral or something like that. Well, then you have the answer in the scripture itself: it didn't come from any man's mind.
You also have the validation from people that are already living this, like me (may be you disregard this, I don't care).
Let's see the example of the versicle where Jesus was praying. Suppose that someone already knows some of the bible teaching, but he/she is asking himself/herself what is the truth. OK, there you have the answer to what the truth is, and what Jesus Christ considered to be the truth.
The person can still don't believe that, because once you start to believe, you don't lose free will, a person can believe some scriptures and other not, of course it is not the best to do (and also it is not coherent).
Different is the case when you don't understand something in the scripture. You can't believe something that you can't understand.
And the reasons why someone is not able to understand some parts of the scriptures may be a lot. Nobody understand all.
So, summarizing, this kind of things make sense only when there are already confidence, not when the person hearing or reading distrust to the one speaking.