I was struck by something that was said last Sunday, questioning the use of spectrum imagery for faith and doubt. The imagery somehow implies that the two fall on opposite ends of some kind of Likert scale (e.g., 5=very good, 1=very bad) rather than the complex interaction and co-existence that is perhaps more common to most people's experience.
It reminds me of a similar pitfall in the use of spectrum imagery for autism, as if we could line people up "on the spectrum" in order of high-functioning to low-functioning, long wavelength to short wavelength, (very good to very bad?) Ummm. Not particularly helpful, to state it mildly.
Some challenges are surely more profound and disturbing than others. There have been some sobering stories echoing through the blogosphere lately. The perfect metaphor, both for autism and for faith, would capture that. Ultraviolet rays can cause skin cancer... look right into the sun too long and you'll burn out your retinas...
On the other hand, which color is the more beautiful, red or violet or something in between? What's the 5, what's the 1, and to what extent must it matter so much? Which person is less a valued and beloved child of God, the one in a place of confident faith or the one eaten to shreds by doubt? The "low-functioning" or "high-functioning" autist?
I think the beauty of the rainbow inherent in the spectrum imagery has a lot going for it, not least the symbolism of the rainbow in the book of Genesis:
And God said, "This is the sign of the covenant which I make between me and you and every living creature that is with you, for all future generations: I set my bow in the cloud, and it shall be a sign of the covenant between me and the earth." Genesis 9:12-13