1 Thessalonians 2:9-13

For you recall, brethren, our labor and hardship, how working night and day so as not to be a burden to any of you, we proclaimed to you the gospel of God. You are witnesses, and so is God, how devoutly and uprightly and blamelessly we behaved toward you believers; just as you know how we were exhorting and encouraging and imploring each one of you as a father would his own children, so that you would walk in a manner worthy of the God who calls you into His own kingdom and glory. For this reason we also constantly thank God that when you received the word of God which you heard from us, you accepted it not as the word of men, but for what it really is, the word of God, which also performs its work in you who believe.