Regardless of your determination, there are questions that must be addressed beyond "acceptance" or "condemnation". Let's start with Marriage.
In the previous essay, I talked about sexual orientation and how it is applied (or not!) to transgender men and women. So then, whom would you allow me (MtF) to marry? Depending on the particular state, I can marry either a man or a woman - so deferring to the law of the land is of no help. All marriage laws say only that a legal marriage is between a man and a woman - there are no other qualifications. And for this exercise I'll avoid a lengthy dissertation on transgender law - legal identification, birth certificates, etc.
Am I to marry a woman? If you hold the belief that "once a man, always a man" (in my case here), then I would be allowed to wed a woman. But that would, from all other outward and physical appearances, sanctify a same-sex relationship. The alternative then would be to allow me to marry a man. But that would then validate my existence as a woman. Which is it? There is no Biblical - or legal - construct to completely deny someone marriage, it only (presumably) defines who someone can marry. What of an existing marriage?
The next question is Atonement. This is a core belief to Christianity, that one can "atone" for their sin and thus receive God's forgiveness. In fact, this principle separates Christianity and Judaism apart from other faiths. Let's make the assumption that transitioning one's gender is a sin. How then do I, as a post-operative transwoman, make atonement? I asked that of a member of a conservative faith and his thought was "well, I guess we'd ask you to start living like a man again." How is that possible? Especially after surgery - which included breast augmentation as well? And it's not that simple. Sure, I could cut my hair, bind my breasts, stop wearing makeup, put on jeans and a t-shirt, belch when I drink beer (just teasin' guys!)....but that's just for appearance sake. I would also need to make the emotional regression as well. And that is akin to giving me the gun to commit suicide. Given the faith-based opposition to physician-assisted death, I would presume this is something that also wouldn't be encouraged.
The suicide rate among transgenders who have not yet transitioned or had surgery is estimated by some to be as high as 50%! And I've already been to that precipice. I cannot imagine what kind of emotional calamity would ensue if one were to be male, then female, then male again. More importantly, neither do you. Incidentally, the incidence of regret for post-surgical transpersons is less than 4% - I am no longer an emotional minefield.
And if I cannot repent or atone for what you consider to be a sin, then what of Communion? There are some churches that withhold the Eucharist from people who don't vote as the church deems appropriate. Transgenders don't "vote" to transition. Jesus shared the meal with Judas...knowing it was he who would betray him. Are transgenders so vile as to be lower than Judas?
What of Baptism? Oh, wait...that's already decided in the Bible! Phillip baptized the Ethiopian eunuch (Acts 8:26-39). How would a church be able to withhold Baptism from the transgender?
What of Ordination? Can I minister? Can one who is a minister, then transitions, remain ordained? There are many who have done so - Rev. Erin Swenson, Rev. Malcom Himschoot, Rev. Justin Tanis. What basis would there be to deny or remove ordination to a transgender? There are some congregations that do not allow women to be in ministry. Would they accept a transman (like Rev. Himschoot)? Would they remove a transwoman (like Rev. Swenson)? Most faiths that denounce homosexuality still allow gays and lesbians to be ordained so long as they remain celibate. What pretext would there be for transgenders?
My point is that "acceptance" or "condemnation" isn't as simple as it may seem. Christian principle requires that a path (though I may not like to walk it) be made available to all. If being transgender is, in your opinion, a sin then design that path.