purushaha sa paraha paartha bhaktyaa labhyastvananyayaa |
yasyaantahasthaani bhootaani yena sarvamidam tatam || 22 ||

That supreme person, in whom all beings are included, by whom all this is pervaded, O Paartha, is obtained through single-pointed devotion.
purushaha : person
saha : that
paraha : supreme
paartha : O Paartha
bhaktyaa : with devotion
labhyaha : obtained
ananyayaa : single pointed
yasya : in whom
antahasthaani : are included
bhootaani : all beings
yena : by whom
sarvam : all
idam : this
tatam : pervaded
With this shloka, Shri Krishna summarizes the topic of liberation. The detail around the creation and dissolution of the universe was meant to highlight the notion that only through liberation can we rise above that endless cycle. Shri Krishna gives us the means for liberation as well as the attributes of the goal which is Ishvara.
Shri Krishna says that liberation is obtained through single-pointed devotion to Ishvara. Single-pointed devotion was covered in chapter six. However, here it is meant to include not just devotion but also karma yoga. If the karma yoga aspect is missing, our vaasanaas or latent desires will remain unfulfilled, pulling us back into the cycle of rebirth so that they will be fulfilled.
Now, what is Ishvara’s connection to creation and dissolution? Ultimately, Ishvara is the cause of all creation. But he is not someone who stands outside his creation. The classic example referenced in this context is that of the potter and the pot. The potter creates the pot out of clay, but remains outside the pot, distinct from the pot. Ishvara is not like that. He is like the ocean that creates waves. The waves are pervaded by the ocean and are also included in the ocean. So is the case with Ishvara. Therefore, Ishvara is everywhere (beyond space) and
ever present (beyond time).
Having conclude the topic of liberation, Shri Krishna begins the last topic of this chapter in the next shloka. He describes the two paths that seekers have to travel through after they pass away.