The four expressions of redemption (in Parshas Va’era): "I will take you out...I will deliver...I will redeem...I will take (you to Me)" - correspond to the four redemptions from the Egyptian and subsequent exiles. This indicates that the following expression, "Veheveisi" (and I will bring you) is a special, superior quality of the era of the future Redemption, which generally is divided into yemot haMoshiach and chad ch’ruv.
Since this fifth expression is mentioned in the context of the redemption from Egypt, it shows that the future Redemption in fact began already with the exodus from Egypt. The Previous Rebbe used to say that ever since the exodus from Egypt we are on our way to the future Redemption.
The Gemara (Baba Kama 22a) states: "R. Yochanan said, '[Man is liable] for his fire, because it is like his arrow'." This means that as soon as one has kindled a fire, he is liable for all resulting damages.
Offhand it would seem that when the fire’s damage actually occurs he is an onus, he is unavoidably prevented from doing anything about it. Why, then, should he be liable for his out-of-control fire? Circumstances beyond a person's control, usually mean an exemption from responsibility?
The liability, however, is for having lit the fire voluntarily in the first place. Liability for any damage that follows as a consequence of a voluntary act is already implied in the act itself.
The measure of goodness exceeds that of punishment. Since damage is seen to have resulted from the initial kindling of the fire, surely this retroactive quality applies to voluntary goodness as well. Thus, from the very moment that G-d promised "I shall bring you" (which refers to the highest level of the future Redemption), this eventuality must in some way have already come to pass.
It would seem, however, that this premise relates only to human actions and not to G-d, for once fire (or an arrow) leaves a person's hand he can no longer control it. With G-d, however, the fire or arrow never really left his “hand”: He is always in full control. So, one can argue that G-d's promise "I will bring you," does not necessarily imply that the result has already been achieved, because as long as the promise has not actually been realized, G-d can seemingly change His mind.
The fact is however, that while G-d does revoke and annul evil decrees, He never repents of good ones. Since "I shall bring you" is certainly a good decree, it is irrevocable; analogous to fire that has left a person's hand.
To be sure, the very idea of compulsion or restriction is altogether not applicable to G-d. Nevertheless, it was G-d's own will - i.e. it is entirely voluntary - that He never revoke a good decree.
In the context of our avodah this means:
When a person realizes that the loftiest levels of the future Redemption through Moshiach, already exist, though merely unrevealed, then the person's service becomes much easier. The individual can more easily overcome all impediments and hindrances in this world in general, and during the conclusion of this final exile in particular.
For in reality, all obstructions and impediments to Torah and mitzvos are ultimately unreal - concealments which serve only to arouse man's hidden abilities to serve G-d.
Moreover, as the Redemption can be said to be already upon us, those concealments and obstructions can be treated as if they are unreal; they truly do not exist.
When we realize that we are dealing with mere illusion (and thus are unaffected by it), we will act with vigor and holiness, and such action will remove even the appearance of concealment.
We will then realize how everything that happened, even things that seemed adverse at the time, were for the good, and ultimately even "for the best."
(Likkutei Sichos v. 1 p. 125)
