24.171
ca-sabda api-arthe, ’api’--avadharane
yatnagraha vina bhakti na janmaya preme
SYNONYMS
ca-sabda—the word ca; api—of the word api; arthe—in the meaning; api avadharane—this api is used in sense of emphasis; yatna-agraha vina—without sincere endeavor; bhakti—devotional service; na—not; janmaya—begets; preme—love of Godhead "The word ca may be used in place of api, which gives emphasis to something.
Thus it means that without sincere endeavor in devotional service, one cannot attain love of Godhead.