1 Thessalonians 5:9

But unto the obtaining of salvation through our Lord Jesus Christ

(αλλα εις περιποιησιν σωτηριας δια του Κυριου ημων Ιησου Χριστου). The difficult word here is περιποιησιν which may be passive, God's possession as in 1 Peter 2:9, or active, obtaining, as in 2 Thessalonians 2:14. The latter is probably the idea here. We are to keep awake so as to fulfil God's purpose (εθετο, appointed, second aorist middle indicative of τιθημ) in calling us. That is our hope of final victory (salvation in this sense).