You can access his work online at www.robgagnon.net.
I would recommend starting with this interview, which gives an overview and defense of his position.
Those who want something more in depth may want to look at a 112-page review written by Prof. Gagnon, available here.
Readers will find treatments here of every major issue in the debate, including discussion and analysis of:
- The different hermeneutical scales or interpretive grids used by proponents and opponents of homosexual practice (pp. 19-25).
- The difficulty in neutralizing Scripture for a pro-homosex agenda (pp. 25-30).
- The nature argument (pp. 30-46).
- The relevant biblical texts and the arguments used to limit their relevance for today's debate: Old Testament (pp. 46-54) and the New Testament (pp. 54-85), including Jesus (pp. 56-62) and Paul (pp. 62-85).
- The three main "new knowledge" arguments for dismissing the biblical witness against homosexual practice: the exploitation argument (pp. 65-76), the orientation argument (pp. 77-79), and the misogyny argument (pp. 80-82).
- Whether homosexual practice is the diet and circumcision issue of today (the Gentile inclusion analogy; pp. 86-90).
- The alleged analogies to slavery, women's roles, divorce/ remarriage and other changes to marriage over the centuries (pp. 90-97) vs. analogies to incest, polysexuality, and pedosexuality (pp. 98-101).
- Manipulative rhetoric in the church debates about homosexuality (pp. 103-114).
- The science side of the debate (pp. 114-30), including the question of the moral relevance of congenital influences and claims to an unchanging orientation (pp. 116-19), the question of whether culture can affect the incidence of homosexuality (pp. 120-25), and the question of whether "gay marriage" is good for society (pp. 125-30).
