Is in-fighting good?

^{In chapel this morning we read a long extract from 1 Corinthians 11 and these two verses stuck with me:}

For, to begin with, when you come together as a church, I hear that there are divisions among you; and to some extent I believe it. Indeed, there have to be factions among you, for only so will it become clear who among you are genuine.

I'm not sure I understand what this means - then if it means what I think it does I'm not sure I agree. Is in-fighting good or is it just part of the discernment process?
Just a passing thought.