From Anas -radiyAllâhu `anhu- who said: 

The Prophet -sallAllâhu 'alaihi wa salam- said: Which of the creation are most amazing in Imaan?
They said: "The Angels".
He -sallAllâhu 'alaihi wa salam- said: The Angels - how could they not have Imaan?!

They said: "The Prophets." 
He -sallAllâhu 'alaihi wa salam- said: The Prophets have Revelation sent to them: how could they not have Imaan?!

They said: "The Companions." 
He -sallAllâhu 'alaihi wa salam- said: The Companions are along with the Prophets, so how could they not have Imaan?!

"Rather the people most amazing in Imaan are: ► a people who will come after you, and who will find a book of the Revelation. So they will have Imaan in it and follow it, so they are the most amazing of the people -(or: the creation)- in Imaan."

[Reported by al-Bazzaar (3/318-319: Kashful-Astaar), and its chain of narration 
was declared 'hasan' by Shaykh al-Albaani in 'as-Sahihah' (no.3215)]

*** [Translated by Abu Talhah Daawud ibn Ronald Burbank]