In Chocolat we have some conflicts going on. Life in the small French village is dominated by the Catholic Church, led by Francise Reynaud. When Vianne shows up, it is Lent, the 40 days before Easter Sunday, when Catholics are supposed to concentrate on their sins, realizing that Christ was crucified for them, and give up some pleasurable thing as a mini-sacrifice, to join in Christ's sacrifice. Lent is a somber time and people are supposed to be somber, until Easter, when they can rejoice again, because Christ rose from the dead. These are the traditions that Vianne encounters when she arrives in Lansquenet-sous-Tannes.
Vianne is a free spirit whose grandmother might even have been a witch. She believes in joy, pleasure, and the symbol of joy and pleasure is her chocolate. To Reynaud, however, chocolate represents sin because the people are tempted by it, in spite of the fact that it is Lent. He thinks that Vianne is leading them further and further into sin. The societal expectation in this town is that one should not eat chocolate during Lent, so when Vianne tempts the people with just the right kind of chocolate, and when she puts these tempting pieces in the window of the shop, Reynaud thinks she is doing the Devil's work. guilt is a big part of the traditions in this town and Vianne is obviously free from this tradition because she is an outsider.
It is the outsiders that bring the joy of life into this town -- both Vianne and Roux and his gypsies. I think the point of it is that the church's traditions have resulted in only somberness, with no joy, and that is not how God wants people to live.