Complex sentence: Voegelin became the leader of an intellectual movement through books he authored like "The New Science of Politics", "Order and History" and "Science, Politics and Gnosticism" this movement opposed what they believed to be unsound Gnostic influences in politics.
Split into simpler sentences: Voegelin became the leader of an intellectual movement through books he authored like "The New Science of Politics", "Order and History" and "Science, Politics and Gnosticism". This movement opposed what they believed to be unsound Gnostic influences in politics.