Dear Rhiannon,
Never knew Jeremy Vine was religious.
http://www.telegraph.co.uk/news/religion/4277439/Christians-are-becoming-social-pariahs-in-Britain-claims-Jeremy-Vine.html
Reading the article, I think the whole point is about professionalism.
If I am a football commentator I may well support a particular team, but my professionalism means I must not let that cloud my judgement as a commentator.
As a political reporter I may well have particular political views, but my professionalism means I must not let that cloud my judgement as a commentator.
Likewise for someone with particular religious views.
That said there are, of course, situations where people are brought in specifically to give their views (op ed pieces) and then that's OK, but there needs to be balance in the broadcast media so we would be rather concerned if all the political personal views were from tories, and likewise we should be concerned if all the religious views come from theists.
But in his role on breakfast show, or Vine's he is there as an impartial reporter and must not allow his personal opinions to cloud the professional requirements of the job.