*Applause* I really like this. The effects fit the verses very well, with the literalization of some of the apparently metaphorical parts working quite well (Nice application of the word "extinguish" with the Shield of Faith, for example). I'm not sure how well this all works in terms of power once one gets into epic levels, but at most all you would have to do is put 2x instead of simply X for some effects. I really like it a great deal, especially the use of aesthetic factors of the Breastplate and Shield into useful signs of the Armor's power.
One suggestion that I would have is to modify the Boots of Preparation a bit, maybe even renaming them the Boots of Peace (I've always heard them referred to as "the Gospel Boots of Peace") and granting immunity to fear effects (The LORD will give you peace). Also, the Helmet of Salvation and the Shield of Faith might grant some bonuses against Mind-Affecting abilities, especially when being manipulated into doing something contrary to Yahw-er, I mean-Heironeous' will. The two of them together could grant immunity, perhaps.
Just a minor nitpick, but the Aura of Good ability would be really cool if you were to make it so that a it doubles (or otherwise gets an obscene boost) when all seven pieces are worn. We are talking about the greatest mortal emissary of Good in the Multiverse, after all.
One question, though. Let's say that the Champion removes the Helmet of Salvation. Would he still need to be on a mission at all times (barring the grace period)? In other words, could a family man be named champion and take a few months to raise his children? I seriously want to use this in a game, so I'd like some details.