Every person is obligated to drink four cups of wine, or grape juice, which is also considered as wine, at the Seder at the appropriate points [see above]. If he drank all four cups at once, he has not fulfilled the obligation. The Talmud notes that this obligation is incumbent upon men, women, and even children, for all were redeemed from Egypt.
The mitzvah of drinking the four cups is so important that even a poor person who is dependent upon charity is required to sell his clothing in order to purchase wine to fulfill this mitzvah.
One who cannot drink wine because it causes him to be uncomfortable, or because he dislikes its taste, must force himself to drink so as to fulfill the mitzvah.
One who has no wine, or if he is ill and fears that drinking wine will be harmful to his health, should consult a competent halachic authority as to what he should do.
The mitzvah of the four cups is optimally fulfilled with red wine. This is based on the verse (Proverbs 23:31) that states: Do not look at the wine as it reddens . This implies that red wine is superior. Red wine also serves as a reminder of the blood of circumcision and the blood of the Paschal sacrifice, for Israel was told before leaving Egypt: Circumcise all your males and then come to offer the sacrifice.
The Torah then tells us that the entire nation did as the were commanded. The blood of circumcision became mingled wit the blood of the sacrifice and it is the merit of these two mitzvot that we commemorate by drinking red wine.
Red wine also serves as a reminder of the blood that was smear on the doorposts as a sign when G-d passed over the homes of Israel not permitting the destruction to strike them. By using red wine thus express our prayer that G-d continue to protect us from all our enemies and foes.
Red wine also serves to protect us and as a reminder of the blood of the Jewish children whom Pharaoh slaughtered so as to bathe in their blood and be cured of his leprosy. This shed blood shall never be silenced. Even three thousand years after this tragedy we shall remember.