1:8 will sustain you. Paul encourages his readers by assuring them that God, who began a work of grace in them, can be trusted to complete it. Indeed, they will be presented “guiltless” at the time of Christ’s return. Note the similarities between vv. 8, 9 and Phil. 1:6, 10 (cf. Eph. 5:26, 27; 1 Thess. 5:23, 24).