It is not true that if we had true faith we would not be sad. Prophets (as), and righteous people experienced a great deal of sadness. The Quran is full of stories in which the central theme is sadness. Sadness is a reality of life. The Quran is not there to eliminate sadness, but to navigate it. Sadness is one of the tests of life, just as happiness, and anger are tests.
‘“My name is Ozymandias, king of kings: Look on my works, ye Mighty, and despair!” Nothing beside remains: round the decay Of that colossal wreck, boundless and bare, The lone and level sands stretch far away.’
They say a picture is worth a thousand words, but a word is worth a million pictures. A billion. As many as there are people who know the word. Each has their own picture, their own meaning of it, in their heads. It’s theirs. It’s unique. And yet they share it with everyone else. And every time they use a word, a single word, they contribute to the creation of the soul of us all.