Earlier quoted context omitted.
It is just a question of orthography. In German, compound nouns are written without space, as a single word. In English, they are usually (but not always) written with space. So "Christmas tree" is "Weinachtsbaum". This is sometimes made out to be much more mysterious than it is, as if German is more "composable" or something, but the only difference is the typographical space. English is just more difficult to spell…
It's not just orthography. English has been influenced by Romance languages and gained a tendency to write "of"s instead of compounds. This reverses the word order (order of words) and adds extra words in between. There is some bit of composability that German has over English though. It's just easier to pick apart words that have been concatenated. Maybe it's because often the first word is in genitive (roughly mean…
Weihnachten comes from weih/geweiht meaning hol{y,ied} night.