I wonder if Archbishop Temple is making exactly that point - that with the loss of faith, more people are shooting arrows with no purpose and with the result of self-destruction. I submit he is making the strong argument that humanity continues to need to believe in something, that we will never be able to find concrete scientific evidence to prove all the mysteries of life.

I agree with post 4 that this quote is referring to the cynical attitude prevalent in today's society.  We want proof for everything before we are willing to believe in it.  Unfortunately, there isn't always proof in the way we want it.  When we refuse to have faith in things that aren't proved, we are the ones that miss out.  We lose faith in religion and in ourselves.  

The attitudes described in the quote, to me, seem like somewhat predictable responses to the many changes that the world was undergoing in the 1940s.

It's no coincidence that today's world seems to fit the same description as we experience many changes too.

To suggest that people are losing their ability to believe or to hope is to ignore the many positive movements which have taken place in the last few years and which continue to occur.

The Arab Spring, for all its difficulty and eventual violence, has been a sustained social and political movement calling for representative government in an area of the world where despotism has too often been the norm. The only way the movement could have gained the success it has is because people believe in change (though that success remains a qualified success, I know).

For me, the quote is referring to a general trend in attitudes today.  We seem to be living (and have been for some time) in a more cynical world.  We find it hard to have faith in anything.  This is partly because we are conditioned to want proof of things before we believe in them.  It is also partly because we have higher expectations and expect all of our public institutions to be perfect.  When they are not, we become angry.

For me, the quote refers to the idea that if we do not focus our energy, then the energy is wasted and only harms us in the end. By not focusing our energy, we are shooting "arrows" at nothing. These arrows, having no target, can only fall back upon us.

This is a quote by William Temple, Archbishop of Canterbury from 1942 to 1944.  It is not clear what you expect in the way of discussion of the quote.  Certainly, it is as applicable to current times as it was to the times in which Temple said this.  However, while Temple believed strongly and acted upon his convictions that Christianity should include social action, it is important, I think, to understand that this quote is about belief or the lack thereof, not a political commentary.  He seems to be saying that without belief in a deity, our unhappiness and complaints are self-destructive.  There are those who would interpret that to mean that we must be able to petition a deity to effectuate change and those who would argue that belief in a higher being gives us the wherewithal to address our needs,  but there are those who would argue that God helps those who help themselves and those who would argue that belief is not a bit necessary to address and alleviate the problems of humanity.  If you can provide some context for us, you are likely to get a meaningful discussion.