What was the major lacking of the church at Ephesus in Revelation?
The church at Ephesus, though doctrinally correct and disciplined, lacked love. In Revelation, the Lord's letter to Ephesus noted their correctness in doctrine and discipline, but their major deficiency was love. Without love, straight doctrines and perfect discipline count for nothing.
Les explains that the Ephesian church was correct in everything—their doctrines were straight and their discipline was in order—yet when the Lord Jesus wrote or spoke that letter to that church, their major lacking was no love. He stresses that it does no good to have all your doctrines straight, and it does no good to have perfect discipline, if there is no love; then it counts for nothing. This matches the Apostle's point to the Corinthians, where even the best gift, prophecy, understanding all mysteries, or faith that could remove mountains amounts to nothing without love.