Yathah karma means Vedic rituals also of course our secular karma and also Vedic meditations that ashritham that is what is meant by according to their knowledge. Depending upon the amount of religious merit you have accumulated you will go to different heavens and you will be born in a more favorable human birth afterwards after your enlightenment. We are all going to become enlightened but really even if we do not become enlightened in this life the very fact that we have engaged in a pursuit of enlightenment there is no backsliding for them they will stay on path.