What was the Apostle Paul so passionate about in the book of Galatians?
He was passionate that the Galatians recognised the importance of the Holy Spirit and had a correct understanding of who He is.
They understood the role that the Spirit played in their conversion, but were missing out on His role as Helper in the ongoing life of a believer. Indeed, the Holy Spirit is more than power to be harnessed. He is a Person to be followed.