Native English speakers should understand this even though the grammar is incorrect. Because this is a coffee shop, the owner thinks everyone should drink more coffee. To rewrite this we'll focus on two points. First, add more words to "you and coffee" to make a sentence. Second, remove "only" and just use "we think." In fact, you can state "you and coffee belong together," because "we think" is implied. Also, capitalize the first letter of every sentence!