CG: if you look at my first post it was asking questions concerning this letter talked about on a YouTube channel
Which letter?
Seriously. You want us to talk about an undated, vaguely referenced, ten year old letter someone (you didn't actually mention WHO authored or sent the letter, although you did refer to WT in your OP) sent to elders in Germany. And you know about this because someone identified as "son of thunder" apparently posted a video on YouTube and talked about it. But you didn't bother to provide links or details for any of this. Do you expect us to search for it?
CG: it's whether this letter is credible
What letter? Oh, the one you didn't post a link or any reference to other than your thread title: "Latest son of thunder video on YouTube and the 07 letter to the elders." And according to your own thread title, that letter is ten years old. Hardly recent.
Also, it's not as if YouTube has any vetting process for reliability or
credibility. Anyone can post pretty much anything on YouTube.