Any life of Christ is going to be extremely difficult to produce because you're dealing with words and actions that are known by virtually every literate person in the Western hemisphere. I think that "King of Kings" reflects the reverence that producers of that time still had for their subject. By the time we get to "The Last Temptation of Christ", the gloves are completely off with regard to the central character and notions of respect. To us in 2003, "King of Kings" seems somewhat unreal, because we just aren't motivated by the same things that informed the filmmakers in 1961. Today, disrespect is seen as intellectualism.
Review of King of Kings
