We all know that we drink four cups of wine/grape juice at the seder, but do you know why? We drink four cups of wine because it symbolizes the jews getting out of Israel for some reason I have no idea why. Also G-d said to the jews "I shall take you out" "I shall rescue you" "I shall redeem you" and "I shall bring you". Four different statements and we drink one glass for every statement. 

haggadah Section: Kadesh