This question - what about the promises (including the 'land grant')? - is the very question Paul is dealing with in his Epistle to the Galatians. Yes: the promises to Abraham were unconditional, and faith was (and still is) the alone instrument through which God grants those promises "to all who believe." This is why, it seems to me, that the underlying argument Paul is making is that the chief promise given to Abraham was that of the Spirit: they must be born again, they must be grafted into Christ, in order to receive the promises. This is not what we would call an antecedent condition -- something that we do that prompts or provokes the thing which follows -- but a consequent condition -- a thing that must follow given a prior thing that has already been done. The giving of the Spirit is the sine qua non of all the other promises; and it is the consummation of God's primordial promise to sovereignly "put enmity between the Serpent's seed and the seed of woman." It's one unfolding promise to bring his people to the consummated kingdom of God, back into his favorable presence, revealed chapter by chapter through history. Being grafted into Christ -- by grace alone, through faith alone, in Christ alone, according to Scripture alone, and to the glory of God alone -- which happens with the giving of the Spirit - - is the means by which God grants "all the promises." The borders of the promised land, expanded once or twice in the OT, are blown wide open to include the entire cosmos: "all authority in heaven and earth has been granted unto me" he says. Christ has, by his perfect obedience, won not just the bordered land in the Middle East, but the entire created cosmos. And he gives it to us: "the meek shall inherit the earth."

But not yet. Now we are pilgrims--"in the world" but not "of the world" precisely because we are "of the kingdom" but not yet "in it" (in the geopolitical sense). Here we have no continuing city. We look for a better, an heavenly city, one with foundations. But Joshua is at the gates, and we pray like Rahab must have: "thy kingdom come."