The "Judaism" of the "Old Testament" is not the Judaism of Jesus and his contemporaries
This is such an important insight. We tend to compress history. It's similar to the way we in the UK talk about the 'Roman period' in Britain, as if the Romans of the 5th century dressed, talked and worshipped the same way as their forebears who arrived in 43 AD.
The Zoroastrian influence on Judaism is fascinating.
By extension, the apocalyptic worldview of JWs - and Evangelical Christianity - finds its roots in Persia.