Paul’s point in 1 Thessalonians 5:1-10 is that because the Thessalonian believers are Christians, they will not suddenly find themselves present during the time of God’s end-time wrath, because “God has not destined them for wrath but for obtaining salvation” (5:9).
The imminent event believers should expect is not wrath but salvation.
This fact should affect my outlook and actions now–
so then let us not sleep as others do, but let us be alert and sober…since we are of the day, let us be sober, having put on the breastplate of faith and love, and as a helmet, the hope of salvation (5:6,8).
The phrase “son of light” is a hebraism denoting an intimate relationship. Those identified as “sons” have as close a relationship to the light as their “parent” does. Thus, “son of” describes what dominates, controls, and is the pervading element of one’s character, whether that be “light” or “darkness.”
Who I am must dictate and be evident in how I live.
Verses 12 and following detail how sons of light and the day should live; the series of admonitions closes with “abstain from every form of evil” (v. 22). As a son of light I should not be involved in any aspect of darkness; rather, I must abstain from whatever is characterized as evil. Thus the immediately following prayer, “May the God of peace sanctify you entirely” (v. 23).
Eschatology–far from being an insignificant or esoteric doctrine–is intended to have an essential role in your life as a believer now.
My anticipation for the future (expectation) must control my actions and direction in the present (employment).