A question for Lutherans - An explanation of “Mystical Union” according to David Hollatz?

[NewTestamentChristian]

I was raised a Catholic and proudly call myself a Cafeteria Catholic. I am open minded when it comes to other churches. I am a fan of Dr. Jordan Cooper and his most recent post on YouTube was regarding the doctrine of mystical union specifically according to the theologian David Hollatz, who I am not at all familiar with. A condensed explanation would be very helpful.

 

[zippy2006]