Commenting on 1 Thessalonians 1:4-7 Fee’s position on the Pauline usage of the word “election” is that of the whole body (i.e. corporate), rather than individual.
The noun “election” itself is found elsewhere in Paul’s letters only in Romans 9-11, all having to do with Israel. Elsewhere Paul uses the verb (Eph 1:4) or the adjective “elect.” Although this language does not occur frequently in his letters, its occurrences in a passage like the present one indicates that it is presuppositional for him. It should be noted that in the present case Paul is thinking of the whole body of Thessalonian believers as elect, not individuals believers. Indeed, although he refers once to an individual as “chosen” (Rom 16:13), his understanding of such election is presuppositionally related to a person’s incorporation into the community of believers. Moreover, for Paul “election” is always a referent to believers, and thus, reflects a reality after the fact, not before; and as here it is always seen as an action of God’s love, and thus it becomes a dynamic force in the life of the believing community. – Gordon Fee “The First Letter and Second Letters to The Thessalonians”, NICNT p31