I appreciate all the comment. It is not magical armor, though it seems like holy symbols, while not actually magical, have some magical (magic type) qualities to it.
Melting it down and reforging, or just trying to remove the symbol are certainly options. I was more worried about how to deal with him wearing it prior to removing the symbol. I think Mercule brings up a very good point about wearing the symbol is basically proclaiming that your deeds are in the service of that god. This obviously would not be good. I think requiring an atonement may be a good way to deal with this should he decide to wear it.
Thanks everybody for your input.