I am no biblical scholar but even this lost soul knows that if you believe in the written word in the various texts among the faiths, God gave humans free will. Why else did Adam screw things up in the Garden of Eden when he did?
This Bishop clearly happens to be under the thumb of Rome, Catholic doctrine having stated that transsexuals and gender reassignment is an affront to their beliefs. If memory serves me well, I am aware that the texts also state that man should obey the laws of our leaders who serve before God in his name. God through Moses did not ban driving with excess alcohol in the blood did he? He allowed our leader to make law according to need.......FREE WILL ...if you please

As for same sex marraige? We call it Civil Partnership here in UK, not marraige. Further, when post operative I choose to marry a man, it will be a marraige in the true meaning because I would be a legally recognised woman marrying a man in accordance with the Marraige Act. Sadly, the Church of England are not obliged to perform the marraige ceremony if they are aware that one of the parties is transsexual, not easy is it?