1TH 3:5

5 [I was] afraid that [Satan], the one who tempts us, had caused you [to stop trusting in Christ. If that had happened], we would have worked uselessly [while we were present with you! So] I sent [Timothy to you] in order to find out whether or not you were [still] trusting [in Christ]. I sent him because I could no longer endure [not knowing ◄about your spiritual condition/whether or not you were still trusting in Christ]►.