What mistake do people make regarding these instructions about worship?
People take these instructions about worship out of context and forget that the primary purpose of everything done in the local congregation is to bring honor and glory to God. Instead of recognizing that aim, they neglect the order and decency the passage requires.
Les explains that Paul knew his writing to Corinth was inspired by the Holy Spirit, so it was not merely man's idea but the Word of God. In verse 40, Paul commands that all things in the local congregation be done decently and in order, because that brings honor and glory to the God we claim to worship. The mistake many people make is taking these things out of context and forgetting that the primary purpose of all that we do is to bring honor and glory to God. Paul also says that if a person chooses ignorance, God gives that prerogative, but the believer should desire to speak forth the Word and not forbid the use of languages.
Let all things be done decently and in order.