In Acts 6:7, we learn that the expression “the Jews” (commonly used throughout Matthew – John), is NOT a blanket description of all the people in Judæa. Aside from the fact that we can read in Mark 12:37 that “the common people heard [Jesus] gladly” we also learn from Acts 6 that many priests in and around Jerusalem became Christians. This shows that many educated people in the general Jewish population were sincere, and were genuinely looking for the Messiah and His kingdom. This also shows us that the biblical expression “the faith” represents the whole gospel message (cf. Acts 16:5), the Lord’s “plan of salvation” (cf. Jude 3), not merely an individual’s own personal faith.
In Simon’s effort to “buy” the apostolic ability to impart miraculous/spiritual gifts to others – through laying hands on them (Acts 8:18-24) – we learn another important fact, from Peter’s response (verse 22). Sin is not restricted to only our actions; Peter’s words show very plainly that Simon’s thought and motive were evil, even though he did not succeed in obtaining what he wanted. Peter instructs him to repent of his evil thought, and to ask God to forgive his evil intention; until he did, Simon could not continue to walk in the light with the Lord (cf. 1 John 1:9).
Acts 10 introduces us to a gentile soldier who becomes a Christian, upon hearing and obeying Peter’s teaching (verses 45-48): Cornelius. Even though Cornelius was described as devout, godfearing, generous and prayerful, it is clear that he was still lost, despite these good qualities! Though what many theologians assert, Acts 11:18 makes is plain that Cornelius was not described as forgiven until after he was baptized.
Paul’s words in Acts 13:38-39 make a clear and important point about the difference between the law of Moses (the “ten commandments”) and the law of Christ. Jesus Himself said that He came to fulfill Moses’ law (to complete, or finish it), not to destroy it (Matthew 5:17). It is in this context that Paul makes it plain that freedom from sin comes through Jesus, not through continued obedience to Moses’ law (verse 39). One who thus claims that Christians are obligated to keep the ten commandments misses the fact that Moses’ law could not (by itself) and cannot free us from sins (cf. also Hebrews 10:1-4).
The Philippians jailer’s question in Acts 16:30 (“Sirs, what must I do to be saved?”), combined the with reply of Paul and Silas, shows that the doctrine of salvation by faith “only” contradicts what the bible actually says. The Philippian jailer correctly understood that he personally had to “do something” in order to be forgiven of his sins; and Paul and Silas specifically did not endorse the “faith only” doctrine by telling him something like “ALL you have to do is believe.” Instead, they not only instructed him to believe in the Lord, but also continued teaching him (and his companions, vs. 32) which obviously included telling him to be baptized (verse 33). Note his reason for rejoicing, in verse 34: Because he had believed in God; but the context makes it clear that he had not believed “only,” but had also obeyed the teaching that produced his belief.