If Christianity should happen to be true - that is to say, if its God is the real God of the universe - then defending it may mean talking about anything and everything.
The most valuable book we can read, about countries we have visited, is that which recalls to us something that we did notice, but did not notice that we noticed.
Unless a man starts afresh about things, he will certainly do nothing effective. Unless a man starts on the strange assumption that he has never existed before, it is quite certain that he will never exist afterwards.