Believing in Moshiach's Arrival

Some people may have problems with what I'm writing, because it sets the actual arrival of Moshiach somewhat far away (i.e. not now), as is inherent to any process. The GR"A in his Peirush to Sifra Ditzniuta wrote almost explicitly that the Moshiach would come after 5666 (this was not a specific year he was trying to state, but rather an explanation on why the Moshiach would come in the last third of the 6th millenium). The GR"A lived from 5480 - 5558. So the GR"A didn't believe Moshiach could come any day? The resolution of this problem lies in the same perush, that we are dealing with if Am Yisrael does not merit the Geulah. The GR"A indeed did not believe that Geulah without merit could happen in his own lifetime. So what is the belief that the Rambam mentions, that "even if he tarries, I shall wait every day that he should come"? Moshiach will come "today", "if you will heed His voice", as it is taught in Sanhedrin 98a. This of course means that Moshiach's immediate arrival is dependent on our merit. What we see from this is the following: The understanding that the latest revelation of Moshiach itself is not on the threshold does not in any way interfere with our pure faith in Moshiach's arrival.