Complex sentence: In the 1980s and 1990s the church became polarized between conservatives, whose main organization was the Contact Roman Catholics, and liberals, whose main organization was the 8 May movement, (Dutch: "Acht Mei-beweging") which was founded in 1985.
Split into simpler sentences: In the 1980s and 1990s the church became polarized between conservatives and liberals. The main organization of the latter was the 8 May movement, (Dutch: "Acht Mei-beweging") that was founded in 1985.