This series of posts explains quite a bit of the problems within the reformed world, its infighting, and the resultant, increasing number of microdenominations.
The problem: overemphasizing either antithesis or common grace instead of holding them together. Err too much on the side of antithesis and you end up sectarian and in a tiny ghetto. Err too much on the side of common grace and you become just like the world.
The fix: if you're naturally bent towards antithesis (like I am) develop friends who are naturally bent towards common grace, and vice versa.