Jamieson, Fausset and Brown on 1 Thessalonians 5:9

9. For--assigning the ground of our "hopes" (1Th 5:8).

appointed us--Translate, "set" (Ac 13:47), in His everlasting purpose of love (1Th 3:3; 2Ti 1:9). Contrast Ro 9:22; Jude 4.

to--that is, unto wrath.

to obtain--Greek, "to the acquisition of salvation"; said, according to Bengel, Of One saved out of a general wreck, when all things else have been lost: so of the elect saved out of the multitude of the lost (2Th 2:13, 14). The fact of God's "appointment" of His grace "through Jesus Christ" (Ep 1:5), takes away the notion of our being able to "acquire" salvation of ourselves. Christ "acquired (so the Greek for 'purchased') the Church (and its salvation) with His own blood" (Ac 20:28); each member is said to be appointed by God to the "acquiring of salvation." In the primary sense, God does the work; in the secondary sense, man does it.