The leaders in view were probably the elders in the Thessalonian church and possibly the deacons and others in positions of leadership (cf. Philippians 1:1; 1 Timothy 5:17). His readers were to appreciate these leaders (plural) for their labors. Their duties, as listed here, are representative, not exhaustive. He charged the believers also to esteem their leaders very highly in love. While some individuals naturally elicit more affection than others, the Thessalonians were deliberately to demonstrate self-sacrificing love to all their leaders. They were to do Song of Solomon , not because they were personally lovable or even admirable, but because of the contribution they made to the other believers. Even if a leader made a small contribution, those profiting from his ministry should appreciate and respect him for his service. Such an attitude would enable the Thessalonians to continue to experience peace in their church ( 1 Thessalonians 5:13). [source][source][source]
"That Paul included such a command shows that relations were not all they could have been." [1][source]
"I have discovered that lack of respect for spiritual leadership is the main cause of church fights and splits." [2][source]
"Leaders can never do their best work when they are subject to carping criticism from those who should be their followers." [3][source]