In high school, I remember a friend of mine sharing how she'd gotten a ride home from someone who had admitted a fear of dying. When my friend shared this, with our prayer circle, the adult leader was excited for her. "How perfect!" He exclaimed, "What an amazing opportunity to share the Gospel. How did you respond?" The truth is, my friend didn't respond. She fell silent and let the other person talk.
Well, today--probably 5 or 6 years later--I was talking to this friend again and this incident came up. She admitted it was something she had always regretted, so she stopped regretting and did something about it. She decided she would send the other girl a facebook message regarding their conversation in the car 6 years ago. Well, days turned to weeks and weeks turned to months and she hadn't sent the message yet. It was as if God told her, "Stop putting this off! Stop putting Me off!" That very night (at 1 am) she wrote a facebook message explaining how we don't need to be fearful of dying because Jesus died for us. She said she doesn't remember what she said, meaning she didn't write it; God did.
I'd be taking creative liberties if I said the girl confessed her sins, accepted Jesus that second, and died the next day. No, instead my friend has heard nothing. And she doesn't expect to, but the funny thing is that she's ok with that.
It's only ok to accept silence after you've done what God has asked you to do. Don't be silent until then. Don't spend 5 or 6 years regretting being silent. Do something about it. Do it now.