Complex sentence: The Society rejects evolution and seeks to undermine its teaching and alter the scientific method to eliminate what it sees as its materialistic, naturalistic, reductionistic and hence science's atheistic underpinnings.
Split into simpler sentences: The Society rejects evolution and seeks to undermine its teaching. Some believe they alter the scientific method to eliminate what it sees as its materialistic, naturalistic, reductionistic and hence science's atheistic underpinnings.