Charles Spurgeon Commentary 1 Thessalonians 1:8-10

"For from you hath sounded forth the word of the Lord, not only in Macedonia and Achaia, but in every place your faith to God-ward is gone forth; so that we need not to speak anything. For they themselves report concerning us what manner of entering in we had unto you; and how ye turned unto God from idols, to serve a living and true God, and to wait for his Son from heaven, whom he raised from the dead, [even] Jesus, who delivereth us from the wrath to come." — 1 Thessalonians 1:8-10 (ASV)

Paul here states that all the churches elsewhere knew what a wonderful time he had had with the Thessalonians, and with what eagerness they had received the gospel, and how they had turned away from their idols very earnestly to become worshippers of the living God. This was a great comfort to Paul, and he speaks about them here with great joy.