I offer this as a teaser toward a clue to interpreting “Spe Salvi.” When Benedict talks about “hope,” he is not talking about a virtue as an accident of a substance. He is talking about the being of the person. And since the person is relational, he is talking about the being of the person as going out of self toward the Other, i.e. God, and others. I submit that this is what he is always talking about, including the first encyclical “Deus Charitas Est.” He is always talking about God. He talks about man in so far as he images God. Since God is three Persons who are One (Communio) because they are intrinsically and constitutively in relation to each other, each Person can only be relation: the Father is the act of engendering Son; the Son is act of obeying and glorifying the Father; the Spirit is the Personification of these two opposing relations.
God is “joyful” in the fullness of each Person as pure relation or relativity (in our abstract way of thinking). God is a triple joy. The imaging of that joy is “hope.” One is hopeful in that one is tending toward a fuller joy than that which is partially possessed at the moment. The secret that lies hidden in the bowels of our very God-like being is that hope is present and increases the more we act-imaging the obedience and glory-giving of the Son to the Father.
Notice that Benedict immediately identifies “faith” and “hope.” As virtues they are not the same. But as the being of the human person they are. Faith and hope and Love (Agape) are distinct angles of perceiving the same reality of the Person as Self-transcending.
Benedict’s thesis in 1954 starts this whole train of thinking off. What is probably the deepest ground of his thinking is the clarification from Bonaventure (and therefore from the Fathers of the Church, especially Gregory of Nyssa (c. 350) that Revelation is not a series of concepts of propositional thinking (like dogmas) but a Person. The Person of Jesus Christ.
Concomitantly, faith is not an acceptance of concepts, but the ontological act of the whole person who proportions himself to be self-gift to the revealing Christ ("Milestones," Ignatius  108-109) Benedict early on says: “Christianity was not only ‘good news’ – the communication of a hitherto known content. In our language we would say: the Christian message was not only ‘informative’ but ‘performative.’" That means: “the Gospel is not merely a communication of things that can be known – it is one that makes things happen and is life changing. The dark door of time, of the future, has been thrown open. The one who has hope lives differently; the one who hopes has been granted the gift of a new life” (3). Notice, again, that “the one who hopes lives differently” and experiences “a new life.” The living differently is the giving of the self. And the “new life” is “to be” outside of oneself. This is Trinitarian life lived in the flesh.
Knowing, then, is not an “informative” act but “performative.” If, as it turns out, that the relational Person of the Son becomes flesh, then what we observe Him to be in our world is prayer. Jesus Christ reveals His most intimate being as the performative action of prayer. And since knowledge is a becoming of the subject known – like is known by like - , in order to know the Person of the Son, one must become the Son by becoming the action that constitutes His most inmost Being: prayer (such as “Abba”).
Again, right after the above, in #3 of the “Spe Salvi,” Benedict relaties that the Ephesians did not have hope because they did not have “God in the world.” Keep in mind, “to have God in the world” is to incarnate that giftedness of self in daily, humdrum activity. “To have God in the world” is to turn every activity into service and to think about others and forget about self. The conceptual “knowledge” of a pagan god is not to make the act of faith which is to transcend the self as gift to the revealing God. Hence, the pagan cannot have hope because he cannot experience – mysteriously – the joy of going out of himself and living for others. Only the one who does this is joyful, and begins to experience hope for definitive joy.