v1-8 - Christians are to live a live that pleases God (v1).
In theological terms, this means that our lives are in a constant process of 'sanctification (v3).'
Becoming sanctified means looking more and more like Christ in all parts of your life, and less and less "like the pagans, who do not know God (v5)."
v9-12 - Christians should be known as people who lead quiet, peaceful lives, minding their own business and working hard. This will win the respect of our communities.
v13-18 - One of the biggest reasons we must read God's Word each day is so that we "do not grieve like the rest of mankind, who have no hope (v13)." We need regular reminders that:
Jesus died and rose again;
Jesus will return with "those who have fallen asleep in him (v14)."
Christ's return will be unmissable (loud and public). When He returns:
"the dead in Christ will rise first (v16)."
After that, all Christians still living "will be caught up together with them in the clouds to meet the Lord in the air (v17)."
These words are given for our peace and encouragement (v18).
There's a tension regarding our good works in the New Testament. On the one hand, we're saved fully by grace, and not by our own efforts. Stacking up enough good deeds does not get you into heaven.
On the other hand, once you've been justified (declared righteous), there's an expectation that you begin to look the way you've been declared to be.
 It is God’s will that you should be sanctified (made holy).
For most of our lives, the lifestyles of Christians who were striving for sanctification didn't look much different from their non-Christian friends and neighbors, who for the most part also lived according to Godly values. But as society rapidly disintegrates around us, you need to be prepared to live in a way that looks drastically different:
 that each of you should learn to control
your own body
in a way that is
holy and honorable,
 not in passionate lust
like the pagans,
who do not know God;
 For God did not call us
to be impure,
but to live a holy life.
In other words: Our unbelieving neighbors can't help the way that act, because they've forgotten how God designed them to be. You, however, are to exercise self control, since not only do you know God, but you've also been commanded to look like Him in every aspect of your life.
Becoming sanctified and living a holy life is not an optional aspect of Christianity:
 Therefore, anyone who
rejects this instruction
does not reject
a human being
but God, the very God who gives you his Holy Spirit.
OLD TESTAMENT REFERENCE:
Leviticus 11:45 (NIV)
I am the Lord, who brought you
up out of Egypt
to be your God;
because I am holy.
Use the comment box below to discuss one or more of these questions:
EYE FOR DETAIL— Paul says that when Jesus comes down from heaven, he will be accompanied by three sounds. What are these three sounds? (See verse 16.)
Based on the second half of this chapter, why should we be optimistic for the future?
Question 1 from The Complete Bible Discussion Guide: New Testament
Follow the AAA Prayer Pattern:
ACKNOWLEDGE WHO GOD IS: Our Father, who is in heaven. Holy is His name.
ALIGN YOUR LIFE WITH GOD'S WILL: Pray that you will more and more reflect His holiness in all you do.
ASK GOD FOR WHAT YOU NEED: