The first-fruit basket symbolises prosperity: the altar symbolises faith. Bringing the fruit to the altar symbolises two things – the farmer‘s acknowledgment that his harvest comes from God, and his undertaking to use his prosperity for purposes that God would approve.
From this subject the Torah reading this Shabbat moves on to the tochechah, the list of punishments that come to the Israelite community if they are sinful.
It seems logical to connect the ritual of the first fruits with the threat of punishment. The connection must surely be that if the Israelite farmer refused to acknowledge God and decided to be greedy and not use his prosperity to strengthen society, both he and his whole community would be in danger of collapse.