This refers to passion, enthusiasm, intensity, over-emphasis.
This has little to do with faith, which means nothing more than the dependency you display when you sit down on a chair.
You rarely think about sitting down. You just do it. You depend entirely on that chair not collapsing under you. You don't expect it to collapse. You don't do a risk analysis. You don't doubt. You simply sit.
This is a better understanding of how faith works. No matter how loudly and widely you proclaim your trust in the chair, your declaration means little. Just sit. Anyone who's interested in noticing you, will. And those who don't care, never will. So why the fervour?
The sad and solemn truth is that humans have a way of encouraging each other to participate in group commitment, and fervour is a first option. Rugby. Cricket. Strictly Come Dancing. Master Chef. Catholicism. Rangers. Protestantism. Manchester United. Al-Quada.
Fervour easily results in over-committed behaviour. You deny thinking for yourself. You refuse the bigger picture. You put passion before sensibility. You make yourself a martyr. You kill others as you martyr yourself.
Whatever, you kill life.
Fervour and faith are not the same.
Faith creates life.
Fervour, done inappropriately, kills it.
If you don't have the intelligence to work out the difference, better back off from making proclamations, especially to yourself. It's not merely about embarrassing yourself: it's about the bigger thing you haven't risen to. Much more is at stake than you realize. Fervour can be stupid and often is...how many beers do you drink because your side has won? Faith is never stupid: it sits, and if the chair collapses, that's a different kind of problem.