Why do some people insist on doing things they know will hurt them? Our daughter just laughs at us when we try to tell her she's going down the wrong road, and she's only hurting herself. It really breaks our hearts. What's wrong with her?
I’m thankful you’re concerned about your daughter and (as you indicate) you’re concerned about her precisely because you know what’s likely to happen to her. Sin always has consequences, and they’re always bad.
But one of the most devastating consequences of sin is spiritual blindness. In other words, sin blinds us to its own terrible consequences. What your daughter is doing isn’t logical, because all she has to do is look around her to see how people’s lives are constantly wrecked because they refuse to do what’s right. But in her spiritual blindness she’s convinced herself that she will be the exception, although she won’t. The Bible bluntly warns, “the wages of sin is death” (Romans 6:23).
Don’t give up praying for her, and don’t stand aside or quit warning your daughter as you have opportunity. But do so with gentleness and love, letting her know that you aren’t trying to run her life, but you love her and care deeply what happens to her. And if (like the prodigal son) she hits bottom someday, she needs to know God still loves her and welcomes her, and so do you.
Above all, ask God to help you be an example to her of Christ’s love and grace. It’s hard to see a son or daughter wander down the wrong road, and sometimes a parent’s words only cause resentment. But God can do what we can’t do, and often our example speaks louder than our words.