What does Acts 10:35 mean?

Peter is in Caesarea Maritima, in a house filled with Gentiles who are anxiously listening to hear how they can worship the one true God. Many of them already follow the Jewish God. They know a bit about Jesus, including His ministry and crucifixion (Acts 10:38–39). Peter is telling them about the resurrection and the fact God has given Jesus the authority to judge the rebellious and save the faithful.

Before Jesus ascended to heaven, He told the disciples they would be His witnesses in Jerusalem, Judea, and Samaria, and to the ends of the earth (Acts 1:8). They spent the first several years focused on Jerusalem. When persecution drove the Jerusalem believers out, they took Jesus' message out to Samaria and Judea. Peter, himself, validated the salvation of Samaritans (Acts 8:14–17). Very likely Philip started the church in Caesarea (Acts 8:26–40). Peter now affirms that anyone who has faith can be saved (see also Ephesians 2:8–9). This verse will be fulfilled more fully in the end times; even Israel's sometimes-enemies will be God's people (Isaiah 19:24–25).

The statement Peter makes here in verse 35 combined with the fact the Holy Spirit came to the crowd before Peter was done with his gospel message (Acts 10:44) make some think the devout will be saved even if they haven't heard the gospel. That's wrong. Cornelius' friends already have a rudimentary understanding of Jesus' work; they are primed to hear and accept more, and Peter does explain that Jesus lives (Acts 10:40), is judge (Acts 10:42), and gives forgiveness of sins to those who believe in Him (Acts 10:43). The Holy Spirit coming on them shows they understand and accept Peter's words (Acts 11:14) and that further explanation or affirmation is not necessary for salvation. Cornelius' acts (Acts 10:2, 4) didn't save him. They were signs of his already strong faith in God (James 2:14–26). He just needed faith in Jesus.