@branman65 @maija @Terry >soteriology
East v West and the different ways of thinking. It could be biological, cultural, or something else. You may find that answer lacking, but it shouldn't be so far fetched in this sphere with the awareness of HBD.
>Theosis
Sanctification is a common word in evangelical Christianity and it's a very similar concept. You are not saved by your Sanctification or Theosis, but they are descriptions of transformation of the soul through continual faith in Christ. One does not "earn" this, but you know that when you devote more of your time and attention to God that there is a noticable difference in how you begin to live and think. It is an iterative process of transformation of the soul, like refinement, where the flaws you later discover were invisible until others were removed.
>lack of clarity
I do agree, but the East Vs West distinction is the why IMO. It's not that it's super esoteric, but it's also not so plainly stated as Western theology. People call the East/West divide the two lungs of the Church with The East being the spiritual or mystical lung and The West being intellectual or rational lung. Not that their isn't plenty of overlap, but the general vibe.
>patristic sources
Most Westerners rely on that even when we don't realize it. We just don't care about the who, unlike the East. But that's all historical contextualization is, and it's hardly different just from a spiritual direction POV.
>vain repetition
The Jesus prayer ("Lord Jesus Christ, Son of God, have mercy on me, a sinner") and other forms of hesychasm are repetitious prayers, but it's not for vanity. It's as much about the prayer itself as it is about adopting the mindset of constantly thinking about Christ and praying without ceasing (1 Thessalonians 5:17)

Sleep well brother.