The big idea (and themes) of 2 Thessalonians is similar to Paul’s first letter to the Christians in the city of Thessalonica. But 2 Thessalonians provides some much needed clarification on a few topics. Here are some of my notes on the book as well as a chart I created for the book. Blessings on you as you study Paul’s second letter to the Christians in the city of Thessalonica. 
BIG IDEA
The Christian life consists of studying God’s Word, enduring suffering now, while also looking to the future return of Christ.
KEY VERSES
With all these things in mind, dear brothers and sisters, stand firm and keep a strong grip on the teaching we passed on to you both in person and by letter. (2 Thessalonians 2:15, NLT)
And now, dear brothers and sisters, we give you this command in the name of our Lord Jesus Christ: Stay away from all believers[ref]Greek from every brother.[/ref] who live idle lives and don’t follow the tradition they received[ref]Some manuscripts read you received.[/ref] from us. (2 Thessalonians 3:6, NLT)