Hey there!
I would like to make one criticism. When you referred to the pagans being satanic cannibalistic etc. it is not true. If it is true, it is most likely a tiny extremist sect. Like christians who murder 'heathens' - does that make all christians murderous people? No.
However, that aside, this was a thought-out, rational, calm argument that was mostly inoffensive and put forward some very good points.
Here are some points if you ever make a follow-up video:
1. Why do people believe in god?
Threats and brainwashing. Threats in the middle ages either believe or die and then parents brainwashed kids for generations to believe. Unintentionally or not, but still brainwashed.
2 If god is imaginary, surely believing won't hurt?
Another reason believing in a fake god is bad: war. Most wars are started by religion. Gulf war I&II, WWII, Crusades...the list goes on. Take SOME muslims who kill innocent men, women and children just because they are a different faith.
They believe in a different invisible man in the sky so they deserve death.
Thanks for taking time to read my letter,
[name]