God said:
As it is, people may deign to not listen to what I say – and they don’t have to, do they? - what makes you think people have to listen to you? What I say is Truth. What you say may be opinion, or it could be Truth, yet who asked you for your opinion or even Truth? You are not the superintendent over other people’s lives, no matter how well-intentioned you may be.
Wait until someone asks, or when it’s your place as with your growing children or a long-time friend who is open to what you think or when someone impinges on your life in some way. Then you uphold your rights by speaking up. You have to speak up. You may find you are not heard, yet it is for you to speak.
There are varieties of circumstances wherein it is your responsibility to speak up, even to a stranger. You could rightfully yell at a stranger who isn’t paying attention and is walking right into a car that is backing out and the driver isn’t paying attention either. You would do well to stop a man from beating his horse. It is not always clear-cut when you must, yet sometimes it is.
There is a big difference between giving advice when it is asked for and rushing in where you have not been invited. Be cautious about intruding on others’ lives.