Your words will not be heard until they are ready to be received.
A friend or loved one is not heeding your warnings because they are too caught up in their emotions. The path before them is heading towards challenging times, but they refuse to examine the warning signs.
As uncomfortable as it to watch on, remember that this is an opportunity for them to grow through experience. We come to learn more about ourselves and the world we reflect through experience. Let the situation run its course and be there when they need you the most.