The author provided the following online background to his book here,
"The body becomes an object to us when it is dysfunctional (or when we reflect upon it as such), but the body as object presupposes a living body, a body which we don’t have but are.
But what does this mean for theology? Lately Christianity has gotten bad reviews on account of its supposed contempt of the body. It denies the bodily pleasures, cultivating an ascetic attitude to the world with roots in a mind-body dualism that privileges the soul on behalf of the body. Friedrich Nietzsche thought that Christianity had given eros poison to drink. Such accusations are strange, however. One of the most distinctive doctrines of Christian theology is the doctrine of the incarnation, namely that the Word of God became present among human beings in bodily form through Jesus Christ. The synoptic Gospels are very clear that Jesus in that sense led a very ordinary, embodied and therefore even painful life; the prologue of the Gospel of John claims explicitly that “the Word became flesh.” Although one should not overdo the dualism of the surrounding Hellenistic philosophy, there is still something quite distinctive in ancient Christian theology’s attempt to stay true to this embodied character of divine revelation experienced through Christ. If, then, Christianity started out in this way, how could it go so wrong (if it indeed did) that it ended up so flagrantly denying the body, as its current detractors suppose?
Moreover, isn’t it funny to hear this accusation of contempt of the body in an age that is itself obsessed with controlling the body? There might indeed be something to say about how traditional ascetic practices relate to embodiment. But our age is an age where everybody seems to be on a diet, literally or metaphorically, and where we lately have given the opportunity to monitor our every heartbeat and download them on the Internet through a watch. The ideals of how we should look invade our daily (or nightly) spheres in an unprecedented way. Who is really the ascetic if we take a closer look? In a way, the current exposure of the body even seems to confirm an ancient theological suspicion that the body isn’t just “there” but has an eschatological telos. The body is not just “given,” but molded by the cultural and social practices to which it belongs. This, as it happens, aligns premodern theological thinking with a lot of contemporary feminist and intersectional theory.
The idea of Heavenly Bodies is to present a comprehensive historical and theoretical account of what embodiment in the Christian tradition could mean. A key to the book is the attempt to show how material Christianity really is, and to stay true to the insight that the body is not, primarily, a thing or an object. The body is not a hindrance for our relationship to God, then. On the contrary, it is a dimension of ourselves whose mystery continually turns toward the invisible. (emphasis is mine)
As one reviewer noted, "This book has all the signs of being a new theological classic. Sigurdson explores a theological anthropology that leads to a profound vision of humans as embodied persons living in God ...... This is not just ivory tower theology, it is highly engaged theology that has profound implications for living the Christian life at a deep level."