What to do?

I've been in this situation before, but I never know quite how to handle it. A friend wants to do something that I think is unwise. I think he's making a bad choice. The pickle is that I want this person to come to an understanding within himself about his path so it's not my place to meddle, but I don't see how this decision can be a good one and I want to save him from the heartache in his future. I know we each have to learn our own lessons, and we can't learn many lessons if we never take a wrong step along way. Yet, I can't help feeling like I'm letting him down by watching him take this step instead of stopping him.

I have to let time and faith take their course. It's tough to do. Keeping my nose out of it is the best thing. Isn't it funny how the best thing is often the hard thing?