Repeating, repeating the same process: sometimes going up, sometimes coming down—this is the material process. Today I am the richest man, and tomorrow I may be a poverty-stricken man in the street. This is going on. As we find in this earth, so also by our pious activities we can be promoted in better planets. Then kṣīṇe puṇye martya-lokaṁ viśanti (BG 9.21). And when the resultant action of pious activities is finished, then again we are driven to this earth or down than this earth. So this is going on.
Lord Caitanya said that ei rūpe brahmāṇḍa bhramite kona bhāgyavān jīva (CC Madhya 19.151): that "This way, this cycle of different species of life, they are going on. So traveling in this way, somebody who is very fortunate, by association of devotees, he gets the seed of devotional service." Ei rūpe brahmāṇḍa bhramite kona bhāgyavān jīva. To achieve the seed of devotional service is a fortunate achievement. It is not very easy, because it ceases the cycle of different transmigration of the soul. By ignorance we take this spot life as permanent settlement, and we think that "We shall live here permanently and make arrangement to live here permanently, and make assets for my children, for my nation." But we do not know that the cycle of transmigration is not fixed up.