Your question is certainly a hard one. I know times of failed ‘God’ conversations with people that I knew well, that have resulted in a real block to further engagement on the topic. In my experience, if the person does not want to have a discussion about God or it is apparent that they really are not in a place where they are desiring truth, then it is normally best to give them space. It is important in those times that whoever you speak with, that they know that you care about them and are happy to listen to any questions they may have when they feel comfortable. The Prodigal son story is a great example of the father allowing the son to leave, but always waiting and hoping for his return. Another scripture that helps me with this question is in John.
John 6: 60-66: When many of his disciples heard it, they said, “This is a hard saying; who can listen to it?” But Jesus, knowing in himself that his disciples were grumbling about this, said to them, “Do you take offense at this? Then what if you were to see the Son of Man ascending to where he was before? It is the Spirit who gives life; the flesh is no help at all. The words that I have spoken to you are spirit and life. But there are some of you who do not believe.” (For Jesus knew from the beginning who those were who did not believe, and who it was who would betray him.) And he said, “This is why I told you that no one can come to me unless it is granted him by the Father.”
After this many of his disciples turned back and no longer walked with him.
The passage reaffirms a few things to me. It is God who always ultimately saves people. If some of Jesus’ followers walked away from His teaching, then some will walk away when we teach. And lastly, when they walked away from Jesus, Jesus did not run after them but let them go. I acknowledge that this is not always the case and discernment is needed in hearing the voice of God and knowing His will. But scripture does support letting the person who rejects Christ to choose his or her own path.
But like you Dan I would love to hear others thoughts .