Not because the topic is wine, but to best answer your question I feel I have to tell you a joke:
A leader of a house of worship was giving a fiery sermon: "If I had all the beer in the world," he said, "I'd take it and throw it in the river; and if I had all the wine in the world, I'd take it and throw it in the river! And if I had all the whiskey in the world, I'd take it and throw it into the river." He sat down. The choir leader then stood up and said with a grin, "All please rise for the singing of: 'We Shall Gather at the River’.”
The above story illustrates two ways to look at wine: The sermonizer believes that wine is intrinsically evil and must be totally avoided, while the choir leader implies that hedonistic immersion in wine is not so bad. The Jewish view is far from both of these views. We believe that the enjoyment of wine, like other physical pleasures, can and should be used in the service of God.
Wine is mentioned in Psalms (104:15) as something that "gladdens the heart of man," and hence it is used to gladden and inspire us at various times — like kiddush on Shabbat (sanctification of Shabbat), at a circumcision and a wedding.
Wine symbolizes a completed and perfected human life. It starts off as an inferior product (grape juice = childhood, immaturity) but must go through fermentation (struggle = challenge of evil) and only then does it become the superior product, wine. We drink it on occasions where we have passed a certain fermentation process (marriage) or at times, like Shabbat, which represent the final product of human life, the World to Come.
