This is very different from the Orthodox conception of divinization: Orthodox Christianity affirms the total uniqueness of the Father and Son as eternally distinct from us. The Father and Son do not possess eternal embodiment, and the principle of the divine does not dwell in us now or in eternity. (Rather, we participate in God through his energies—in other words, by an act of his grace, not by our own nature.)
There are other ways of relating God to the arena of human history. In his mature theology, Karl Barth did not view God's eternity in opposition to time, but as distinct though inseparably related to time. This conception allowed him to see time in constructive relation to eternity, but without placing God in time. It also allowed him to view Jesus—though not the Father—as the enfleshed Word at every angle, whose eternal nature was distinct and prior to, but never separate from, his earthly nature and existence.
Much to Ponder
Webb poses key questions regarding Mormon metaphysics and the notion of God's eternal embodiment: First: "Does it [metaphysical materialism] make sense of Mormonism?" Second: "Does it make sense period?" Third: "Can metaphysical materialism be substituted for metaphysical immaterialism without radically altering traditional Christian beliefs?" And fourth: "If so, what does that say about the promise of Mormonism for ecumenical dialogue and Christian unity?"
I answer "yes" to the first question. Webb's intriguing proposal sheds light on key aspects of Mormon teaching. As for the second question, I have serious doubts about the coherence and internal consistency of a doctrine assuming matter to be "the very stuff of the divine." To the third question, I can only answer "no," given my belief in the uniqueness of the incarnation and Christ's person and work.
In response to the fourth and final question, I don't believe we need to abandon concern for cultivating dialogue with Mormonism (though I believe we should take care to distinguish this from the dialogue between branches of historic Christendom). There is much to ponder and appreciate in Mormonism: namely, its profound sense of communal identity, its desire to elevate Christ, and its rejection of a secularist rendering of life. Interreligious discourse that is rich and robust does not entail having to agree with various groups at every turn. It is important to work through differing convictions in a civil manner to shed further light on the multiplicity of perspectives, including irreconcilable differences, for the furtherance of shared interests and concerns and work toward the common good. (I highly recommend that evangelicals interested in interreligious discourse join the Evangelical Chapter of the Foundation for Religious Diplomacy, where we seek to be "trustworthy rivals" with Mormons, Buddhists, Muslims, Secular Humanists, and others.)