I think J C Ryle in his book 'Holiness' handles situations like this very well. There are sins of commission and there are sins of omission. These sins are irrespective of race religion or age. The sense that all is not well concerning Nanna is sense enough warning that something needs to be done about it. Treating people with dignity of course is the best place to begin.

Jesus when he spoke to the man from Gadarene first put him into his right mind. The he was able to communicate life changing truth to the once crazed man. Revival was the result of this effort by Jesus. Jesus knew what confronted him at that point in time.

When he spoke with the Samaritan woman at the well the situation was different but the questions were the same. Who am I and where did I come from? Perhaps we could say it this way, who am I and what is wrong with me.

Jean Paul Sartre French existentialist philosopher said this, "Something rather than nothing is out there; furthermore something in contrast to that something is also there; I am there you are there." So Sartre realised that there were only two basic philosophic questions that confront men and women, the questions of metaphysics of being and of morals.

If you think about it, Nanna's problem is the same as the man from gadarene's or the Samaritan woman at the well. Even Nanna's can lose their way sometimes as we do, but Jesus brings us back into the fold by putting us first in our right minds then gives us truth concerning the real issues.

It is important to realise that the non-Christian reasons upon a different framework for appraoching truth and knowledge. Sin means one thing to the Christian, but the non-Christian doesn't even have a framework to tell them what sin is let alone provide them with any certainty of knowledge at all.