Since being baptized, I have been interested and active in soul winning. I taught Bible classes for children, worked with VBS, worked with a bus ministry, showed the Jule Miller Film Strips, and sent out Bible correspondence course lessons. I attend worship and Bible study three times a week.
When my husband was in AA, I met a lady there who asked me to be her sponsor in AlAnon, so I did. She called me often in the middle of the night and I always helped her. She surprised me one night by asking, "Should I be baptized?" To this day I can not recall what I said to her, but I know I normally would have said, "Yes, let's study" or something like that. But for some reason, I did not do that. I never had any phone call after that where we discussed religion or salvation. Even when we moved away, she kept in touch calling me for suggestions on how to live with her alcoholic husband. Eventually, she developed a liver disease due to her own drinking. We talked about that a lot. When we went back to her town to visit, she always came to visit us and talk with us and tell us how she was doing on the transplant list. She was getting very ill and eventually, she died.
How will the Lord deal with me over this? I have no idea why my mind went black when I talked to this woman, but thinking about teaching her the gospel never came to mind and it was not like me! I fear this lady is lost because of me and fear that I will pay with my own soul for not teaching a person who simply asked, "Do I need to be baptized?" and trusted me to answer her. If I will die with her blood on my hands, I want to know so I can begin to accept it. If there is a way to be forgiven, I want to know that, too.
Yes, you passed up an opportunity to teach someone. It probably wasn't the right choice at the time. I recall some events in my own past where I wished I was wise enough back then to have made some other choice. Yet, as John points out, we all make mistakes -- we all sin -- and that is why we admit our faults to God and then press on to be better servants of God (I John 1:5-2:1).
Not to excuse the choice, but I have had people call me, leaving desperate messages that they really need to change and live a Christian life. I call them back as soon as I receive the message and in the vast majority of the cases, the person was drunk or high on drugs when they first called. By the time I was able to call back, they had sobered up and either didn't remember calling me or was too embarrassed about their behavior to talk to me. Since your friend never brought up the topic again, I suspect that is what happened with her. What I can't figure out is that it sounds like you didn't try to bring up the topic later, or you did but you are dismissing it because she didn't respond.
If you look at Ezekiel 3:16-21, Ezekiel makes a good illustration of what all of us should do when teaching. It is our responsibility to let others know that they are in danger and that there is a path to safety. Whether the person heeds the warning or not is his own responsibility.
You passed up one opportunity to teach your friend, but we don't know if your friend was even in a teachable state at that time or not. That is something only God knows. So apologize to God for failing to pursue an opportunity to spread His gospel and move on resolved to be more watchful.
If your friend missed heaven, one missed opportunity is not enough to change someone's destiny. The Bible shows that God gives people many chances to make good decisions. There were years where your friend could have brought up the topic again. I suspect there were many times you tried to approach the topic and got pushed away. That was her choice -- one you could never make for her.