May’s faith is of no significance here. If she started making policies directly based on scripture then yeah, it would. But saying ‘I talked to god and he agreed it was a good idea to put billboards on lorries telling immigrants to go home’ is no different to simply having thought of it yourself.
If you believe that you had a conversation with God and received an answer then you are either a) schizophrenic or b) His prophet. Either way, you shouldn’t be prime minister, you have other pressing business.
In this case though it’s just cynical politicking. If you look at Theresa May’s decision making, it’s obviously not influenced by the word of Christ.