Whatever one of us asked the other to do - it was assumed the asker would weigh all the consequences - the other would do. Thus one might wake the other in the night and ask for a cup of water; and the other would peacefully (and sleepily) fetch it. We, in fact, defined courtesy as 'a cup of water in the night'. And we considered it a very great courtesy to ask for the cup as well as to fetch it.
It is not possible to be 'incidentally a Christian.' The fact of Christianity must be overwhelmingly first or nothing. This suggests a reason for the dislike of Christians by nominal or non-Christians: their lives contain no overwhelming first but many balances.