Or look it like this:
The Civil War, there were two major issues- the universal 'wrong' of slavery coupled with the disintegration of the Union. Some Fi users (my guess is) would say, 'who gives a shit about the union? It's just some meaningless construct. What matters is we rid the world of slavery, because it is wrong, and that is the most important thing." But a Fe user (my guess is) would say, "There is value to the Union, to a community of persons. It is vital that we don't sever this permanently. We need to find a solution which is amenable to both sides." But both of these are good, important things. And yes, you do need both.
As far as the OP goes, I'd imagine trying to tap into Fi isn't going to produce the healthiest use of the function. I would think it would be best to rely on his Ni+Fe in order to pay attention to what really matters to him. For example, I don't view my marriage as important due to the social constructs of it; I view it as important because it makes me happy, it makes my husband happy, it makes my kids happy, and it would be wrong of me to hurt them, or to hurt myself. I want to be a good person of integrity, so I stay true to it. A Fe user may view it differently, however. (I don't really know. That's why I say 'may'.) But any way, both of us is going to see the marriage as a good thing of value.
But as far as the latest Church scandal goes, I would say the cover-up of the sexual abuse was Fe gone awry- "protect the institution at all costs", while the Fi would say, "This is a house of cards. Your desire to protect this is killing it." I'm not saying there aren't situations of Fi gone awry, cause there sure are, I'm just using this as an example of the sort Poki, I imagine, is thinking.
EDIT: Actually, Fi gone awry, in the case of the church, I would think would be the cultural shift toward Fi in the sixties of moral relativism- 'do your own thing' made people begin to see the lack of importance of tradition/ a church community. Vatican II (making the church more 'modern') caused it to lose a lot of it's significance. I think the Fi desire to make it more personal was a worthy goal, but it can lead to people thinking, 'Eh, why do I need this? I can be with God alone anywhere!' (As a Fi user, not saying I disagree with this- cause I stopped going to church years ago for this very reason, not to mention being guided by own internal values- but not exactly healthy as far as survival of an institution goes.)