If it already existed, it is easier to achieve it

Noah’s Ark was similar to the Redemption; the wolf and sheep lived peacefully there, similar to how it will be in the time of Moshiach. We understand from this that it is easier to work towards the Redemption, since this state already existed once, and it is easier to achieve something that has already happened than something new that has never happened in the world.

(The Rebbe King Moshiach Shlita)