"The Christian is dancing."
Hmmm. It was quite popular in communities where children were learning about Christian religion (to be precise - not just "about", not "Christians believe that..." but "we believe that...", with praying etc. - but it's rather not a good place to start a discussion about what religion lessons look like in Poland and religion at all, too many Polish people here :P). I remember it from Christian camps where I went when I was 10-13, so it appeared at least 11 years ago. Probably the video is a part of a TV program for Christian children, "Ziarno" ("seed"). Popularity - I think because of youtube, before that only some children (and maybe their parents ;) ) knew it, then somebody found it and put the video there... :P