<p>1:4 <em>Knowing, brothers beloved of God, your first calling</em>- Paul was sure they had been called because he had preached the Gospel to them (:5). The call is therefore in the Gospel. Those who hear the Gospel are called; those who have been invited to Christ cannot ever claim they were not invited or not called. Paul doesn't want them to be in any doubt about their calling- he wanted them to 'know' it. And yet Paul is so positive about these rather weak Thessalonians when talking to God about them; see on :3. The Lord's mediation for us is similar.</p>