Is It A Good Idea

Everythings going to be okay. Everything is going to be alright. Ususally these are helpful phrases that make a certain situation a LITTLE less stressful but at the same time is it really sincere when no one else knows what's REALLY going on? There's always more to the story than people put out or when they tell the story it's only THIER side so you pity them or what not. So is it really a good idea to say everythings ok to a random person when really we don't know the full story or problem? Is it fair to the person on the other end of the story? Or does it not matter because said other person will never know? I mean if you really think about you also could be completely right about the situation. Sorry for the rambling but is it a good idea?