J. Wheeler: Good question about church membership. The New Testament makes several references to “the church” (Greek ekklesia), but it gives us no guidance as to what constitutes “church membership.” Obviously there are many different perspectives today as to how one becomes a member of a local church. And it seems clear to me that many church members are not really believers. So no, not everyone who is a church member is saved.
I don’t think anyone apart from God can really know who is going to heaven. But I like your use of the word “sanctifies,” which refers to a process of becoming holy or growing in one’s relationship with God. It is incumbent on all believers to submit themselves to God and ask him to work in their lives. Paul’s instruction in Romans 12:2 is very pertinent: “Don’t copy the behavior and customs of this world, but let God transform you into a new person by changing the way you think. Then you will learn to know God’s will for you, which is good and pleasing and perfect.”

Carl, in Acts 19:1-7 we read about believers (literally, disciples) in Ephesus who had been baptized, probably by Apollos, a Jewish convert. We read in Acts 18:25 that Apollos “knew only about John’s baptism.” For background on “John’s baptism,” we can look at Luke 3:3, where we read, “John went from place to place on both sides of the Jordan River, preaching that people should be baptized to show that they had repented of their sins and turned to God to be forgiven.” John told the people who came to hear him preach, “I baptize you with water; but someone is coming soon who is greater than I am–so much greater that I’m not even worthy to be his slave and untie the straps of his sandals. He will baptize you with the Holy Spirit and with fire” (Luke 3:16). So John’s baptism anticipated the ministry of Jesus, but John’s own ministry was carried out before the crucifixion and resurrection of Jesus and the subsequent coming of the Holy Spirit.

The New Testament assumes that believers in Jesus have also received the Holy Spirit, as evidenced by Paul’s question to the Ephesian believers: “Did you receive the Holy Spirit when you believed?” (Acts 19:2). Their response that they had been baptized with “the baptism of John” suggests that they were not yet fully believers in Jesus. They had repented of their sins (as taught by John), but maybe they did not even know about the life, death, and resurrection of Jesus. “As soon as they heard [about Jesus], they were baptized in the name of the Lord Jesus. Then when Paul laid his hands on them, the Holy Spirit came on them, and they spoke in other tongues and prophesied” (Acts 19:5-6).

For us today, we receive the Holy Spirit when we become believers in Jesus. Various churches have different interpretations as to whether believers must also be physically baptized, and there are various understandings of what it means to be “baptized with the Holy Spirit” (Acts 1:5; 11:16). Paul assumes that all true believers have received the Holy Spirit, and the fruit of the Spirit is shown in their lives (Gal. 5:22-26).

Dennis, the terms “born again” and “saved” can be used interchangeably in English, just as the underlying Greek terms in the New Testament are used to mean the same thing. In the passages from 1 Peter (quoted above), Peter is writing to believers in regions of what is now Turkey, and the tone and content of his letter suggest that his audience was comprised of both Jewish and Gentile believers. So his term “born again” applies to both Jews and Gentiles. Similarly, the Greek word for “saved” (which is used 107 times in the New Testament) applies to both Jews and Gentiles. For example, Jesus uses it for Jews (e.g., Matt. 19:25; Luke 7:50), and the same term is used for Cornelius (Acts 11:14), who was a Gentile.

Thank you for your question! I have reached out to Mark Taylor for a response and will post it as soon as I hear back. Thanks again!