How do we know the doctrine of singleness is true?

Recordings in scripture affirm the doctrine of singleness, particularly as depicted in Matthew 6:22-23. Here, Christ emphasizes that our spiritual insight—represented by the eye—must be singularly focused on Him to illuminate our lives. The passage indicates that a divided attention leads to darkness, while true focus leads to spiritual clarity. The teachings of Jesus and the apostles consistently reinforce this doctrine, presenting it as essential for genuine faith and obedience to God.