Jesus will return unexpectedly, “as a thief in the night,” so believers should always be ready for His arrival. Paul calls the Thessalonians “sons of light” and “sons of the day,” showing that believers should not walk blindly, in ignorance of this coming day. God has destined us for the final rescue from this sinful world and our sinful natures when Jesus will return and right all things, so we should encourage one another with this in mind.
We can anticipate Jesus’s return with hope and love. We should encourage one another to live faithfully now so that we are ready for His second coming. Paul summarizes what sanctified living looks like for the Thessalonians, because his hope for them is that they will be prepared to be approved and receive a reward upon Jesus’s arrival. The Thessalonians should support their leaders, be at peace with one another, help those who are afraid or are immature, and live life full of prayer with a joyful attitude, staying away from all evil.
God is faithful, and His plans will come to pass. Paul asks for prayer, encourages unity, and emphasizes one last time the goal of living a God-honoring life apart from the world, so that our body and soul will be blameless when Jesus returns.