<p>3:5 <em>For this cause I also, when I could no longer endure it, sent Timothy- </em>&quot;No longer endure it&quot; is a repetition of :1. Paul was so anxious about their faith because the nature of his eternity was tied up with whether they would endure in faith (see on 2:19,20). To send Timothy was a major sacrifice- see on :1,2. Notice how there was no distinction between Paul&rsquo;s will (<em>&ldquo;When I could endure it no longer, I also sent...</em>&rdquo; 1 Thess. 3:5), and that of his fellow workers (<em>&ldquo;When we could endure it no longer&hellip; we sent...&rdquo;</em> 1 Thess. 3:1,2). He assigned to his brethren his own feelings and decisions.</p><p><em>That I might know your faith, lest by any means the tempter had tempted you and our labour should be in vain</em>- Despite having had these questions about the state of their faith, he had always been positive about their faith and endurance, even telling God about it (1:2,3). This means that despite his doubts about them and valid concerns, he believed in their status in Christ and felt towards them accordingly. This is no simplistic positivism, but a studied outworking of faith in what it means for a person to be in Christ. The source of the opposition at Thessalonica was the Jews, as 2:14-16 and Acts 17 makes clear. They were the tempters, the satan of 2:18. He personifies the entire Judaist opposition and Jewish plot against his work as a singular adversary. We note he likens the Judaizers tempting the Corinthians to the tempting serpent in Eden (2 Cor. 11:3). To go off to Judaism would cost them their salvation; and Paul's labour would have been in vain. But he has stated in 2:1 that his work with them so far had not been in vain.</p>