What warnings does the Bible give about spiritual blindness?

The teachings in Luke 6:39-45 carry a stern warning about the consequences of spiritual blindness. Jesus compares false teachers to the blind leading the blind, emphasizing that both will fall into a metaphorical ditch. This depicts the grave danger of following leaders who are themselves lost. Believers are encouraged to scrutinize teachings to ensure they align with biblical truth because neglecting this can result in eternal loss. The responsibility lies with both teachers and congregants alike to seek the light of Scripture and reject unsound doctrines for the sake of their souls.