Ephesians 4:21

“if so be that ye heard Him, and were taught in Him, even as truth is in Jesus”.

“If so be”: “This condition of reality does not intend to raise. doubt; it does, however, intend to remind Paul's readers of the unquestionable fact that they heard and were taught so that if any one of them did not learn, the fault does not lie with their teachers or with what these taught” (Lenski p. 560). “Heard Him”: Heard preaching about Him or heard His word taught (1 Corinthians 14:37). Remember, Christ was preaching through His apostles and prophets. “Were taught in Him”: New converts need much more than just instruction concerning what to do to be saved. These Christians were "taught" after they heard about Christ. The Bible stresses the need for new converts to be engaged in continual instruction (Matthew 28:19; Acts 2:42; Acts 14:22; Acts 19:9). Paul had personally grounded many of these Christians in the faith (Acts 19:9). “Even as truth is in Jesus”: Notice how Paul easily switches from "Christ" (Ephesians 4:20) to "Jesus" (Ephesians 4:21). The historical Jesus is the same as the heavenly Christ, and real spiritual truth only exists in connection with Jesus Christ (John 14:6; John 8:31; John 17:17; John 16:13). Real truth is not in any other religious founder. Truth is not in Buddha, Mohammed or Joseph Smith. “Let it not be said (this may be implied) that the instruction received by Gentile Christians was one whit less genuinely ‘truth as it is in Jesus' than the instruction received by those ‘who first hoped in Christ' (Ephesians 1:12)” (Bruce p. 357).

“ To learn Christ is to grasp the new creation which He has made possible, and the entirely new life which results from it. It is nothing less than putting off our old humanity like. rotten garment and putting on like clean clothing the new humanity recreated in God's image” (Stott p. 180).