Check out these various studies in Paul's Letters
CAUTION: Most of the studies below are survey studies aimed at discussing the purposes of each Epistle as a whole and rightly applying it based on a correct holistic understanding. Although some of the details in each Letter are, of course, always included, a good study Bible should be consulted for help with specific details. The goal of each worksheet and the accompanying notes is to promote meditation on and discussion.
One of the main purposes of Paul's fatherly, first letter to the Thessalonians was to encourage the mostly Gentile believers in the young church to live pure and God-centered lives (2:10-12). In the final chapter, there are many commands which show what was involved in this. How would you group the commands in 5:14-22? The chart below shows one way of doing so.
The first group of commands (in 5:14-15) have to with interpersonal relationships and problems within the church. The second group (5:16-18) involves prayer, praise, and thanksgiving and is therefore more focused on God himself. The third group (5:19-22) has to do with being careful about preaching and teaching. Messages needed to be tested to see if they really were of God or not since false teaching would lead to ungodly living.
The new believers had been saved to serve the living and true God (1:9), and they had received the Holy Spirit in order to enable their service. This was a great provision and joy to them (1:8, 5:16), but they, of course, were still imperfect (5:19). Therefore, after the many commands, Paul wrote about the future perfecting work of God (5:23-24).
Though they were exhorted to abstain from every form of evil (5:22) and had been enabled to do so by the Holy Spirit (4:3-8), Paul knew that they would all fail to some extent. Therefore the Apostle did not end with this powerful command (5:22). Like all earnest believers who delight in God's will and word, the Thessalonians needed to trust God for his future work of sanctification (5:23-24) as well as do their best in serving the Lord in the present. (Remember First John 1:9.)
The commands in 5:14-22 were not given without the promise in 5:23-24, and the precious promise in 5:23-24 did not nullify the responsibility to serve seen in the commands.
As Paul's shortest pastoral Epistle, Titus is much more concise than First and Second Timothy, even though it covers some of the same topics. For instance, Paul wrote to Titus about the qualifications of elders (1:5-9) as he did to Timothy as well (1 Tim. 3:1-7), but the apostle did not write to Titus about deacons (1 Tim. 3:8-13). Perhaps this was because the situation on Crete needed correction on a more foundational level. So rather than writing a long letter to Titus, Paul just wrote about basic matters beginning with the sinful, sick culture.
Conditions on the island of Crete, such as its fine harbors, made it possible for Cretans to be idle and lazy but still well fed (1:10-12). Moreover, the sinful aspect of the culture, including rampant dishonesty (1:2, 12), had impacted everyone on the island so that the testimonies of the new churches that Paul had started were not yet as they should have been (3:14).
The most urgent need was for godly leaders (elders) to be appointed in each city (1:5-9) so that the sinful way of life of the islanders and the false teaching and beliefs behind such could be confronted (1:10-16). This is probably why the appointment of good leaders is mentioned up front in Titus 1:5-9, unlike in First Timothy where it comes in chapter three.
In order for there to be godly men and families, Titus was to teach and exhort older men, older women, younger men, and slaves in the churches about how to live (2:1-10). Yet, interestingly, he was not commanded to teach the younger women. That was to be done by older women (2:4-5), since Titus needed to be careful to avoid temptation and any appearance of impurity.
All of the teaching and admonition of believers was to result in the doing of good and having a good testimony (2:5, 10). Notice how often good and good works are mentioned (1:8,16, 2:3,5,10,14, 3:1,8,14). Lest this stress be misunderstood, however, Paul also made it clear that salvation is not through our good works (3:5,7) but through the work of Christ and the grace of God (3:4-7). This is in agreement with Paul's teaching in Ephesians 2:8-10 as well as with Peter's in Second Peter 1:5-11.
That which was good was also healthy (1:9,13, 2:1,2,8), especially the healthy teaching (1:9, 2:1,8). So God's and Paul's missionary plan was to establish healthy, biblical churches on Crete that would have a good testimony to those outside because the church members lived differently (2:14). Only churches with such a difference have a lasting impact on those around them.
Conversely, Paul did not, for instance, give advice on how to attract people to church through seeker-sensitive social events. Moreover, for the most part the apostle was negative about Cretan culture, though to be fair he did cite a Cretan poet to help make a negative point in 1:12. Church growth literature tends to be much too positive about contemporary cultural.
In addition, much missions literature stresses the need to adapt to the culture, citing First Corinthians 9:22. This is as it should be, but Titus 2:10-16 and the need to oppose sinful aspects of a culture are often overlooked in the process. It is grave error to be culturally-centered instead of Christ-centered.
Philemon is Paul's shortest Epistle, but it is also the apostle's most relational Letter. He acted as a mediator between Philemon, a prominent Christian from Colosse, and Onesimus his runaway slave who may have stolen some things from Philemon. (Both Philemon and Onesimus had been saved through Paul's ministry.) So one of the main applications of this short book is that we should, like Paul, attempt to help other believers work together well and overcome offenses. Therefore Philemon is somewhat like Philippians 4:1-6. Reconciliation, of course, often involves repentance and forgiveness.
Philemon is triangular because it is primarily about three main characters. So one of the best ways to study the Epistle is to think about and discuss Philemon, Onesimus, and Paul one after another. The three were all alike in some ways, but their differences lead to different practical applications. How should we be like Onesimus, Philemon, and Paul?
Philemon is somewhat controversial because Paul did not directly condemn slavery. However, he did speak about the relationship of Philemon and Onesimus as brothers in Christ. Thus Paul opposed the abuses involved in slavery. (The respectful tone of the letter and the lack of many commands fits well with this.) For more on slavery, see Colossians 4:1 and the notes in a good study Bible.
Sadly, Philemon is neglected by most theologians because it is practical and relatively easy to understand compared to Romans chapters one through 11, for instance. Yet, the concept of one person taking on the debt of another (19) is an important aspect of the doctrine of salvation and is in line with Paul's teaching elsewhere. Moreover, practical theology and topics like mutual forgiveness and praying for one another should not be skipped over lightly. Philemon is profoundly practical for all believers even though it was originally addressed to an individual.