Regarding the question of man vs god. If one interrogates the mystical and spiritual traditions in all cultures around the world, one will come to see that they all point to a unanimous message: man can become god. This is the mystical meaning behind alchemy, the transmutation of mortal man into immortal god. It has been the preoccupation of the ancients. It clearly also is the aim of Yoga: self-realization; realizing ones god-potential.
I understand it in lesser sentimental and dramatic terms: Humans have an infinite potential. In fact this infinite potential exists within every atom, and it not until the DNA sequences itself in the form of human, that we can become self-aware of that potential. A dog is most likely not aware of that potential; but humans are. Of course humans can live like dogs: eat, drink, sleep, excrete, have sex and play - but then they are not really doing their dharma as humans according to Yoga - a human is meant for contemplation, a human is meant to become a god. It is like an intermediate step between the ascent of animal to god.
Humans need to actualize the enormous potential that exists within them. We already have a glimpse of that enormous potential, because we have seen it in other humans: In the intelligence of Einstein, in the vast creativity of Beethovan, in the compassion of Buddha, in the devotion and love of Jesus, in the superhuman powers of Krishna. Even lesser examples: in humans with photographic memories, in monks who can can control their heart beat, their body temperature, or simply in the triumphs of human spirit in many people over suffering and tragedy.
In other words humans have immense power. Some are using a fraction of it, others are using a lot more of it. Disciplines like Kriya Yoga are for those humans who want to use more of that power.
I was telling the same to my friend recently whose read a bit of Neo-Vedanta stuff and is now resigned to the idea that there is no free will, and there is no point doing or trying anything, because it is all presdestined by a higher power anyway. The same thinking is exhibited by religious people, who naively think that by surrendering all their will to some higher power they are becoming more evolved, or they are being spiritual. In actual fact they are just denying the use of their own power by giving it away to destiny or some god, or even another person(Jesus, Krishna, Mohammed or the pope)
If you want to remain mortal then deny your power. If you want to become an immortal god then you need to use more of your power.