Wow it's so hard to check the date of a post you are replying to!! Those of us who do must waste so much time that we couldn't possibly have lives as well.
Apart from actually missing the date of the post your reply also made absolutely no sense. The person didn't even say anything about there can't be christians in Japan. They were just a little unhappy to learn that christianity was supposedly on the rise in the country. Now who wouldn't be unhappy to hear that?