What does 1 Timothy 4:1 mean?
The beginning of chapter 4 transitions from Paul's personal and church policy, which was the focus of chapters 1–3, to the issue of false teachers. Verses 1 through 5 focus on the various dangers presented by these deceivers.The opening phrase "the Spirit expressly says" is often met with confusion. There is no specific quotation in Scripture which matches this wording. Some believe that Paul was referring to information given directly to Paul in a special revelation. Others believe this might be a reference to some other, non-biblical work. However, the most likely interpretation is also the simplest. This idea that false teachers would arise to deceive Christians is a clear doctrine of Jesus (Mark 13:22), and is seen in other parts of the Bible. So, while the specific words in 1 Timothy 4:1 are not found elsewhere in the Bible, they reflect a truth which the Holy Spirit has "expressly" taught.
Paul's reference to "later times" is similar to that of 2 Timothy 3:1. Paul certainly has in mind the time he actually wrote this letter, since he spoke of these actions as taking place in Ephesus. However, this is a general forward-looking statement, incorporating all time until the eventual return of Christ.
Paul's prediction is that certain people associated with the Christian church will "depart." This verse, in and of itself, gives no specific indication whether these people are true believers who were deceived, or unbelievers. In either case, they were part of the church family, but later separate themselves from the faith. The motivation for their departure will be spiritual deception. This might involve actual spirit worship, common in the ancient world. Or, this may be a vague reference to false teachings (1 Timothy 4:3).
Paul often notes that any doctrines which contradict the gospel are inherently evil (Galatians 1:8–9). Saying that these are the teachings of "demons" is a potent way of declaring that their claims are contrary to the "sound doctrine" which was given by Christ (James 3:15).