He who knows at the same time both Vidya and Avidya,
crosses over death by Avidya
and attains immortality through Vidya.
Those who follow or “worship” the path of selfishness and pleasure (Avidya), without knowing anything higher, necessarily fall into darkness; but those who worship or cherish Vidya (knowledge) for mere intellectual pride and satisfaction, fall into greater darkness, because the opportunity which they misuse is greater.
In the subsequent verses Vidya and Avidya are used in something the same sense as “faith” and “works” in the Christian Bible; neither alone can lead to the ultimate goal, but when taken together they carry one to the Highest. Work done with unselfish motive purifies the mind and enables man to perceive his undying nature. From this he gains inevitably a knowledge of God, because the Soul and God are one and inseparable; and when he knows himself to be one with the Supreme and Indestructible Whole, he realizes his immortality.
They fall into blind darkness who worship the Unmanifested
and they fall into greater darkness who worship the manifested.
The Upanishads translated by Swami Paramananda
Text from: Project Gutenberg