In Bernard Shaw's Saint Joan, how do Joan's struggles relate to the struggles we face in todays modern age society?Because Joan is a woman she...

I think one approach you might want to consider is how
males oppose Joan not because of her gender necessarily, but because they are concerned
abotut the effect that supporting her would have on their own power. Thus it is that
Bishop Cauchon, for example, is far more concerned about Joan's individualistic views
and how they threaten the church's position, which is why he labels her a heretic rather
than a witch. In the same scene, Warwick shows this same tendency by fearing an increase
in the power of the nobility at the expense of the rights of the feudal class. It
appears that Joan is presented as a dangerous pawn that is unaware of her effect and how
others view her, and is sacrificed for greater goals that she is naive
about.

I am sure there are lots of comparisons that can be
drawn with similar situations where somebody sets out to do something and make a
difference for all of the right reasons, wanting to do good, but in the end finds out
that their actions and motives are used and manipulated by others for their own purposes
and goals, such as charity work or work for an NGO or development
organisation.