What does 1 Thessalonians 1:8 say about the Thessalonians' faith spreading?
In 1 Thessalonians 1:8, Paul writes that the Thessalonians' faith toward God was spread abroad in every place, so that he and his companions needed not to speak anything. Their testimony went out so widely that Paul did not have to tell others about it.
Les explains that the Thessalonians were formerly just as pagan as anyone else, but once Paul saw them converted out of paganism, they shared their faith wherever they went. They could not shut those people's mouths. Because their faith toward God was spread abroad in every place, Paul and his companions did not need to speak anything—the testimony of these new believers was doing the work. This happened everywhere Paul went, simply because he preached Christ crucified, buried, and risen from the dead, and that is the power of the Gospel.
For from you sounded out the word of the Lord not only in Macedonia and Achaia, but also in every place your faith to God-ward is spread abroad; so that we need not to speak any thing.