In the book of Acts, written by Luke, Jesus begins to fulfill his promise to the apostles that the Holy Spirit would guide them into “all the truth” (John 16:13; cf. John 14:16,26). After his resurrection, and shortly before ascending to heaven, he told them: “…you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth” (Acts 1:8).
In Acts 2:4 we read that “…they were all filled with the Holy Spirit and began to speak in different tongues [i.e., languages], as the Spirit enabled them to proclaim” (NAB-A). This process is commonly referred to as “inspiration.” The Spirit “enabled them to proclaim.” Put another way, men who were inspired were “moved by the Holy Spirit” to speak (and write) the word of God (2 Peter 1:21).
The fact that God fulfilled his promise is seen by the apostle Paul’s affirmation to the elders (or overseers) of the church in Ephesus. He told them: “…I did not shrink from proclaiming to you the entire plan of God” (Acts 20:27, NAB-A). But if it is necessary, as some affirm, to adhere to teachings and traditions received after the completion of the New Testament in order to have a “fuller revelation” from God, then Paul lied by saying that he proclaimed “the entire plan of God.” But God doesn’t lie, and Paul didn’t either.
God fulfilled his promise through the apostle Paul, who went on to write thirteen or fourteen letters of the New Testament. By means of Paul’s writings, the Holy Spirit, the only true and infallible “Vicar of Christ,” has been with the church “always” (John 14:16).
The apostle Peter also wrote about what God had done through the apostles and prophets of the first century with these words: “His divine power has bestowed on us everything that makes for life and devotion through the knowledge of him who called us by his own glory and power” (2 Peter 1:3, NAB-A). Peter said that by means of “knowledge” we have been given “everything” necessary for life and devotion to God. This knowledge has been revealed in the New Testament.
Would it be necessary for so-called “successors” of Peter to reveal new truths after the apostles of the first century had been guided into “all the truth” (John 16:13)? Did Peter believe that new traditions and “dogmas” would be revealed to the church at a later date? The answer of the Scriptures is no. The Holy Spirit would continue to guide future generations by means of this all-sufficient revelation.
Jude, written between 68-70 AD, clearly states that “the faith … was once for all handed down” to Christians (Jude 3, NASB). A lexicographer by the name of Henry Thayer says that the Greek word translated “once for all” is used in reference to that which is “of perpetual validity and never needs repetition.” Another example of this word is found in 1 Peter 3:18 which says: “For Christ also suffered for sins once, the righteous for the sake of the unrighteous, that he might lead you to God” (NAB-A).
Just as Christ suffered only one time, so had “all the truth” (John 16:13) been revealed one time through the apostles and prophets of the first century. God did not plan to reveal more “truths” to the church at a later date. A “fuller revelation” in the distant future would not be necessary if “the faith” (the teachings of Christ) had already been handed down “once for all” in the first century!