You must know that there are different tastes. There are also different powers of digestion. God has made different religions and creeds to suit different aspirants. By no means all are fit for the Knowledge of Brahman. Therefore the worship of God with form has been provided. The mother brings home a fish for her children. She curries part of the fish, part she fries, and with another part she makes pilau. By no means all can digest the pilau. So she makes fish soup for those who have weak stomachs. Further, some want pickled or fried fish. There are different temperaments. There are differences in the capacity to comprehend.