1) V'Hotzeiti - Took us out
2) V'Hitzalti - Saved us
3) V'Ga'alti - Redeemed us
4) V'Lakachti - Took us as a people
However, there is a fifth verb that created a dispute among the Sages as to whether or not it refers to part of the redemptive process or if it is talking about the future journey to Israel:
5) V'Heiveiti - Will bring us
According to some, there should only be four cups; according to others, there should really be five cups. Therefore, a compromise was made in which four cups would be drank at the Seder, but a fifth would be poured and left untouched. When Mashiach (Messiah) comes, we will have many important ethical and ritual questions that need answers, including whether or not there should be a fifth cup at the Seder. Since Jewish tradition has it that Eliyahu HaNavi (Elijah the prophet) will precede the coming of Mashiach and announce his presence, he will be able to answer these questions. Hence, this cup symbolizes all the disputes throughout history that only Eliyahu HaNavi can resolve.
As long as the Kos Shel Eliyahu remains on our tables, we are reminded that there is still work to be done. Most specifically, we need to undo the vice that put us into our current exile: sinat chinam. As Jews, we are responsible for showing the rest of the world how to act, which includes teaching people to use their God-given talents for good. But to succeed in this mission, we first need to free ourselves from the "slavery" of hating fellow Jews who differ from us and embrace the "freedom" of recognizing the importance of every human being. The very fact we have not yet been redeemed is an indication that we need to work on our interpersonal behavior. Only then can we merit the God-given peace associated with the Messianic age.
From the emerging nuclear threat in Iran to the vying for control over Jerusalem - there are extraordinary events happening right now that were predicted to occur just before the Final Redemption. This may compel some people to wait for the world to change for the better without much personal effort. While it's fine to anticipate the great days ahead of us, it's important to remember that amazing things only happen as a result of hard work. Therefore, we should be proactive in supporting, defending, and praying for Israel in the macro, as well as becoming kinder, gentler, and more decent human beings in the micro. By improving ourselves and showing concern for others, we are participating in the betterment of the Jewish people.
Just as God kept his promise of redeeming us from Egyptian slavery, we can have faith that He will redeem us from our current exile as well. Although the redemption will only happen when God decides it is time, we can compel Him to bring that great day sooner by correcting our interpersonal flaws. One tradition states that just as our previous redemption occurred during the Hebrew month of Nissan, so too will the future redemption happen during this period. Following this approach, perhaps when we open our front doors during the Seder for Eliyahu HaNavi, he will actually be there - heralding the Messianic age and Final Redemption.