I wrote in a comment, regarding Mashiah: "but still believe that he can come at any time"
In my haste I implied that one must belief that Mashiah can come at any time. R. Henkin e-mailed me that this is incorrect, as he explained in his book. Here is a translation of a letter of his that is posted online:
In the matter of waiting for the redemption, I wrote in Bnei Banim vol. 3 ma'amar 3 and in the name of my great grandfather zt"l that the obligation is to anticipate every day that Mashiah will come and not necessarily that he will come on each day. It seems that the world has trouble with this. Many prefer their current situation and place and their anticipation of Mashiah is only a recitation of words. But others want him to come so much that they believe he has already come.In the above quoted chapter in Bnei Banim, R. Henkin cites a number of talmudic passages that render a required belief that Mashiah can come every day difficult. For example, the Gemara in Eruvin 43b states that Mashiah will not come on Shabbat or holidays. Elsewhere, Tannaim argue whether the redemption will be in Nissan or Tishrei. Clearly, they were of the view that Mashiah cannot come on any day. Rather, one each day the anticipated that he will come sometime.
The Lubavitcher Rebbe (Likutei Sihos, vol. 23 p. 394) originally understood the wording of the Ani Ma'amin - "ahakeh lo be-khol yom she-yavo" - as meaning that the waiting has to be every day, as R. Henkin holds. However, the Lubavitcher Rebbe eventually rejected this explanation because, if that was the intent, the Ani Ma'amin should have read "be-khol yom ahakeh lo she-yavo. Therefore, he concludes that this must be referring to Mashiah ben Yosef, who can come on any day, rather than The Mashiah (ben David) who is limited from coming on certain days.
(Compare the Hebrew version with the English translation:
As has been explained, this does not mean that every day we should wait for Mashiach's ultimate coming, but that every day, we should wait expectantly for Mashiach to come on that very day.From the footnote to that text, it is clear that it is intended to be a tranlsation of what I summarized above. But instead it turns it inside out. You would not think that Hasidim who revere their rebbe so much would distort his words.)