Those interested in materialistic activities remain in the cycle of birth and death. Pravrtti-marga, or the inclination to stay in the material world to enjoy varieties of sense gratification, has been explained in the previous verse - SB 7.15.50-51

Expressions researched:
"Those interested in materialistic activities remain in the cycle of birth and death"

SB Canto 7

Those interested in materialistic activities remain in the cycle of birth and death.

SB 7.15.52, Purport:

Those interested in materialistic activities remain in the cycle of birth and death. Pravṛtti-mārga, or the inclination to stay in the material world to enjoy varieties of sense gratification, has been explained in the previous verse. Now, in this verse, it is explained that one who has perfect brahminical knowledge rejects the process of elevation to higher planets and accepts nivṛtti-mārga; in other words, he prepares himself to go back home, back to Godhead. Those who are not brāhmaṇas but atheists do not know what is pravṛtti-mārga or nivṛtti-mārga; they simply want to obtain pleasure at any cost. Our Kṛṣṇa consciousness movement is therefore training devotees to give up the pravṛtti-mārga and accept the nivṛtti-mārga in order to return home, back to Godhead. This is a little difficult to understand, but it is very easy if one takes to Kṛṣṇa consciousness seriously and tries to understand Kṛṣṇa. A Kṛṣṇa conscious person can understand that performing yajña according to the karma-kāṇḍa system is a useless waste of time and that merely giving up the karma-kāṇḍa and accepting the process of speculation is also unfruitful.