It depends, of course, on what you mean by ‘practising Christian’. If you mean one who has practised Christianity in every respect at every moment of his life, then there is only One on record—Christ Himself. In that sense there are no practising Christians, but only Christians who, in varying degrees try to practise it and fail in varying degrees and then start again. A perfect practise of Christianity would, of course, consist in a perfect imitation of the life of Christ—I mean, in so far as it was applicable in one’s own particular circumstances. Not in an idiotic sense—it doesn’t mean that every Christian should grow a beard, or be a bachelor, or become a travelling preacher. It means that every single act and feeling, every experience, whether pleasant or unpleasant, must be referred to God. It means looking at everything as something that comes from Him, and always looking to Him and asking His will first, and saying, ‘How would He wish me to deal with this?’
Editor's note: One thing that bugs me to no end is when writers—or at least smart people—put the period or comma outside the quotation marks. This is never, under any circumstance, to be done... unless you are a British writer, as Mr. Lewis was. If English-speaking Europeans are your market, then you may do so. That is why it is such in the quote above. And why s is substituted for z or c in many words. 
