The Anglican Church in Australia (Sydney Diocese) for the recent Synod has produced a report arguing that supporting transitioning is a sin:
See:
https://www.sds.asn.au/sites/default/files/Gender%20Identity.Report2017.FINAL.v2.pdfAnglican Church Diosese of Sydney
The Church report states that:-
The human person is a psychosomatic unity, where body and soul come into being at the same time and, in this life and the next, exist together. Embodiment is integral to human identity, and biological sex is a fundamental aspect of embodiment. Preserving the integrity of body and soul, and honouring and protecting the biologically-sexed body that God has given are necessary for human flourishing.
The binary distinctions of male and female are to be embraced and upheld in the lives of Christian men and women respectively, and expressed in culturally appropriate ways that conform to Scripture.
However, Churches, schools, and other Anglican organisations are to be places where all people, including those who experience gender identity issues and incongruence, are welcomed, loved and supported and helped to live in obedience to Christ.
Practical love of those experiencing gender identity issues and incongruence entails:
a) faithfulness to the teaching of the Bible
b) compassion, and active love, care, and support
c) rejection of all bullying, ridicule, mistreatment, and abuse of gender non-conforming people
d) evidence-based pathways for treatment, which are consistent with Scripture,
e) ensuring that churches and organisations are adequately informed about gender identity issues and incongruence, and the relevant teaching of the Bible
For those experiencing gender incongruence
You are made in the image of God and you will find your identity in Christ. Therefore, we encourage you:
(a) to seek treatment options that aim for the integrity of psycho-somatic unity (your birth sex);
(b) to seek regular Christian fellowship;
(c) to share your struggles with some mature Christian people so you can receive Christian compassion and support, as well as accountability and encouragement;
(d) to know that while gender dysphoria may be a lifelong battle for you, nothing can separate you from the love of God in Christ Jesus, and God will be patient with you, and his grace will sustain you; and
(e) to fix your eyes on Jesus and look forward to wholeness and relief of suffering in the new creation.
The 47 page report to Members of the church goes onto say that:
The current trend in treatment is to 'transition' or change the person's appearance and real lived experience (RLE)—socially, hormonally, and surgically—to that of their felt gender identity.
Yet such an approach is at odds with God's sovereign purpose in creating us as sexed, embodied beings with psychosomatic unity, whose bodies will be perfected in the new creation, and who are now to serve God and his world with our bodies, in gendered relationships, even while we are subjected to the groaning and limitations of this present age. The experience of felt incongruence between the objective givenness of our sexed bodies and subjective gender identity belongs to the groaning of this creation as it waits for the return of Christ and the new creation (Rom. 8:20–23).
In this way, the current trend in treatment offered by healthcare professionals, and promoted by transgender activists, creates additional strains on those with gender identity issues, as it promises a resolution of this tension that is at odds with God's purposes, and offers false hope, as biological sex cannot be changed.
Moreover, the Bible addresses some practices involved in gender transitioning. Cross-gender dressing and behaviour, and blurring the distinctions between male and female are condemned in both Old and New Testaments (Deut. 22:5; 1 Cor. 6:9; 11:4–15). Presenting oneself in public as the opposite sex necessarily involves disguise and falsehood (viz; the intention to "pass" as the opposite sex) which are likewise condemned (Lev. 19:11; Eph. 4:25; Col. 3:9). Wilfully depriving one's spouse of their conjugal rights (e.g., as a consequence of male-to-female cross-hormone therapy in an otherwise healthy body, or in the mistaken belief it is 'same-sex sexual activity') is also sin (1 Cor. 7:3–5; Heb. 13:4). Sexual relations between people of the same biological sex is same-sex sexual activity—even if those involved regard themselves, and are legally regarded, to be of opposing gender—and is therefore sinful (e.g., Lev. 18:22; 20:13; Rom. 1:26–27; 1 Cor. 6:9–10; 1 Tim. 1:10)