Just look at some of the ways Christians are described on this thread. I even saw one comment despairing that this couple might breed, and pass their beliefs onto their children. Sure, people are free to be Christians in the UK without harassment or discrimination, as long as they don'tactuallylive out their faith in society or express their beliefs in the workplace or in public.
As long as you're one of those nice Christians that doesn't actually take the Bible seriously, or talk about your faith, you're perfectly safe.
i) With regards to the bit in bold above. That is exactly the way it should be if expressing a belief causes offense. Why would you think it should be any different? Would you advocate for a nazi to be allowed to voice their views that the holocaust was a great thing in your workplace?
ii) Discriminating against discriminators isn't really discrimination (what a mouthful). Christians choose to believe their nonsensical rules, granted many are indoctrinated into it at young age, but it's still a choice. If Christians don't want to be discriminated against for being homophobic then all they need to do is stop being homophobic. It's not hard, literally millions, including some Christians, manage it everyday. You don't even have to stop believe it really, just keep it deep inside your black heart.
iii) Christians shouldn't even take the bible seriously. I mean it's literally a collection of specifically selected tales that tell the story a bunch of men wanted it to tell thousands of years ago. Take the Infancy of James and Infancy of Thomas for example. Both written around the same period of time; James tells the story of the immaculate conception and the birth of Jesus, while Thomas tells of how Jesus was a bit of a dick as a kid. Guess which one was deemed cannon and which was classed as fiction?
Not only that but it's been mistransalted and misinterpreted thousands of times, is filled with contradictions and inaccuracies, and is still to this day reinterpreted to suit the society that it's being preached too. 100 or so years ago it was frowned upon to eat meat on a Friday. Now, not so much.
Tl:dr - keep your beliefs to yourself and you'll not be targeted for being a *t.