The effects of karma may be very old indeed. We are suffering or enjoying the results of our activities from time immemorial, but we can change the results of our karma, or our activity, and this change depends on the perfection of our knowledge. We are engaged in various activities. Undoubtedly we do not know what sort of activities we should adopt to gain relief from the actions and reactions of all these activities, but this is also explained in the Bhagavad-gītā.
The position of īśvara, the Supreme Lord, is that of supreme consciousness. The jīvas, or the living entities, being parts and parcels of the Supreme Lord, are also conscious. Both the living entity and material nature are explained as prakṛti, the energy of the Supreme Lord, but one of the two, the jīva, is conscious. The other prakṛti is not conscious. That is the difference. Therefore the jīva-prakṛti is called superior because the jīva has consciousness which is similar to the Lord's.