Corinth (v.1) spanned the Isthmus of Corinth, so it had a sea-port on two coasts. That gave it twice the commercial traffic of other seaports, and twice their wealth. Paul didn’t want them to think he was after their money, so rather than go straight to the synagogue as he usually did, he got a job (v.2,3). Before he became a rabbi, his father taught him to make tents, as the Lord’s father taught Him to be a carpenter.
That was the perfect trade for the apostle who tells us to rightly divide the Word (IITim.2:15). We get accused of cutting up the Bible and throwing away the parts not written to us, but that’s not how Paul made tents! He sewed the parts back together to make something useful, and we put the divided parts of the Bible together to make the Bible useful.
Claudius may have told Jews to leave Rome (v.2) because they’ve always been hated due to their laws and customs that made them different (cf.Jer.12:9)—so don’t be prejudiced!
Paul preached harder when Silas and Timothy arrived (18:5) because he was refreshed by their fellowship, and by the news Timothy brought him from Thessalonica that they were withstanding the persecution storm he raised there (IThes.3: 1-8). You should be in church so you can be encouraged in your stand for the truth when you see others standing for it.
The Jews contradicted themselves when they tried to argue with Paul, which made them mad enough to blaspheme (18: 6). So he shook off their dust (cf.Mt.10:5,7,14). That was his way of washing his hands of their blood (cf.Mt.27: 4). If he hadn’t warned them to get saved, he would have been guilty of their blood (cf.Ezek.3:18,19) because a dispensation was committed to him (ICor.9:16,17). If he didn’t dispense it to leaders (Acts 20:26) we wouldn’t have a gospel go preach. We know we’re not guilty of anyone’s blood because we don’t have the authority to make pronouncements like Paul did (18:6). Our motive to share the gospel is the love of Christ (IICor.5:14), not the fear of what He’ll do if we don’t.
In Acts 13:46, Paul turned to the Gentiles, but he said “henceforth” he’d “go” to them (18:6). He just went to a hillfull of them (17:22-31), so here he meant from that point on he’d go to Gentiles in a different way, by sending them epistles (cf.28:28’s sent). The “now” in IThessalonians 3:6 suggests he wrote that letter here, which some say was his first.
If you commit three crimes, it’s often three strikes and you’re out. They lock you up forever. God gave Israel three strikes (Acts 13:46; 18:6; 28:28), then locked them up—but only till after the Rapture, when they’ll be His people again.
Justus (18:7) must have been a Gentile or he’d have been in the synagogue with the Jews. He worshipped God, but never became a Jew, perhaps because he thought Jesus was their Christ, and those Jews didn’t. So when he overheard Paul preach He was Christ from his house next door, he invited Paul in to hear more. That’s where Paul started the church! Justus’ salvation provoked Crispus to emulation (18:8cf.Ro. 11:13,14), i.e., to want to equal or excel Paul at what he was doing. Crispus got so jealous that he was never able to reach the Gentile next door, he joined Paul to help him reach them.
It provoked the rest of the Jews to envy when they saw how “many” of the Corinthian Gentiles got saved (v.8)—and when they heard them speak with tongues (ICor.14). Tongues were a sign to the unbelieving Jews next door (1:22; 14:22). Signs belonged to Israel (Ps.74:9), but God took them away when they disobeyed Him—like when they killed Christ! When God gave their Acts 2:4 sign of tongues to the Gentiles, their envy drove them to try to kill Paul (cf.ICor.2: 3), so the Lord assured him of his safety (Acts 18:9,10). The “much people” He saw in Corinth were the humble kind (ICor.1:26-28). Hearing there were “many”, Paul stayed longer in Corinth than any other city so far (Acts 18:11).
A video of this message is available on YouTube: “The Establishing Of The Corinthian Church” Acts 18:1-11