As per Bhagavad Gita doctrine of evolution and karma are the controlling factors of cosmic system. Both these precepts of spirituality happened automatically, not even in control of God Almighty. From beginning of time God Almighty, Brahman in Hinduism acts as a Dhrishta (onlooker) never interfering with creation of his!
Law of karma says as we indulged accordingly shaped our destiny. If we have a lot of Punya Karma in our balance then after death of present body our soul atman manifests a new human form to start new journey of life.
In this new manifestation what if Punya Karma of previous lives manifested all of a sudden. One is bound to reap a landfall, become extremely lucky at times winning a great lottery. What if someone has a huge balance of negative karma transferred from previous manifestations? Untold sufferings would befall before this person.
As per this analogy Lord Krishna in Bhagavad Gita advises human beings to indulge in positivity, good karma all the time. Only then we could maintain a positive residual balance of karma all the time.
As per Bhagavad Gita in present life if we suddenly become lucky, a luck that does not result from karma indulged by us in present life time then a positive residual balance of karma from previous manifestations precipitated.
Lord Krishna advises in Bhagavad Gita that one must never think of life in terms of getting lucky. We must only strive for indulgence in positive karma, good karma all the time. That would automatically result in good times ahead.
There are instances in world when a commoner won a lottery amounting to above 100 million dollars. This definitely did not precipitate from workings of present life time. If we have a balance of positive karma, Punya karma in our balance and we get lucky then it resulted from karma indulged by us in past lives. We are ourselves squarely responsible for been lucky in present life.
God absolutely had no role in people become lucky on earthly plane.