This whole section contains very powerful expressions of emotion and affection from Paul toward the Thessalonians. Phrases like torn away,
in person not in heart,
and great desire to see you
reflect the deep love and concern that Paul had for the Thessalonians. Though Timothy would have already assured them of Paul’s love during his visit to Thessalonica (see 1 Thessalonians 3:1–5), these phrases in the present letter—which followed Timothy’s visit—would have served to reassure and strengthen the Thessalonians, both in their relationship with Paul and in their faith in the Lord Jesus Christ.
17 But since we were torn away from you, brothers, for a short time, in person not in heart, we endeavored the more eagerly and with great desire to see you face to face,