In the letter to the Galatians, Paul makes the case that salvation comes to Gentiles through faith in Christ alone (Ehrman 348). From the letter we are able to deduce that other missionaries, claiming that observance of Torah as summed up in the rite of circumcision (Osiek 424), have arrived in Galatia, introducing new criteria for salvation. Based on what Paul says in the letter, it appears that these missionaries may also charge that Paul has tampered with the gospel received from Jesus’ own followers.  In response to these claims, Paul includes within the epistle a large passage of autobiographical information (Galatians 1:11-2:21), which can be broken down into several episodes, each of which is designed to lend support to Paul’s gospel of salvation through faith alone.
The book of Acts tells us that on the day of Pentecost, following the death, resurrection and ascension of Jesus into heaven, the Holy Spirit came and filled the apostles and they began to speak in other languages (Acts 2:4). In his subsequent explanation of this strange event, Luke has Peter quote from the Old Testament prophet Joel, explaining that in the last days, the Holy Spirit will be poured out on all people with attendant signs that include prophecy, dreams and visions (Acts 2:17).