The unsophisticated and unrealistic way in which Francis tried to make the Sermon on the Mount the rule of his 'new People' is not understood properly if we designate it as 'idealism'...it is understandable only as...eschatological confidence..
A couple of common-sense objections to the Immaculate Conception help us to understand the eschatological nature of this dogma. First, it is asked how Mary could have benefited from the salvation Christ won by his Passion and Resurrection before these things happened. Second, if Mary was free of both the guilt and the effects of original sin from the first moment of her conception, what need did she have of the redemption Christ was to win for us?
These objections reveal an overly temporal and mechanical imagination surrounding the Resurrection of Christ and the salvation that it is for us. The Resurrection matters precisely because it is an eschatological event; it is the end and destiny of the creation made historical by revelation.
This is why Paul, in Romans 4, is able to suggest that Abraham's faith that God could bring forth descendants from the bodies of himself and Sarah, which were 'as good as dead,' is a sort of occult faith in the Resurrection. Abraham believed that God could bring a fresh and new life from a creation that had become old and dead in the corruption inherited from our first parents, and that God would do just that through his body and that of his wife.
Isaac, is then, the first visible light of the dawn of Resurrection faith. As the power of this eschaton-made-history rolls through time, it prepares Mary to be the new and final Ark in which the full inauguration of the End will come into the world.