1Therefore when we could endure it no longer, we thought it best to be left behind at Athens alone,
2and we sent Timothy, our brother and God's fellow worker in the gospel of Christ, to strengthen and encourage you as to your faith,
3so that no one would be disturbed by these afflictions; for you yourselves know that we have been destined for this.
When it became clear that Paul wasn’t going to be able to make the trip to Thessalonica to visit his beloved church, he decided to stay at Athens and send Timothy on ahead in his stead. He wanted Timothy to strengthen and encourage these believers, particularly in light of the fact that they were suffering, being afflicted by the Jews. Yet they had already been taught early on to expect persecution for following Christ.
4For indeed when we were with you, we kept telling you in advance that we were going to suffer affliction; and so it came to pass, as you know.
5For this reason, when I could endure it no longer, I also sent to find out about your faith, for fear that the tempter might have tempted you, and our labor would be in vain.
As 2 Timothy 3:12 makes clear, all who desire to live godly in Christ will be persecuted. Paul, Timothy, and Silvanus knew enough from personal experience (Paul having been a persecutor of the greatest severity and determination before his conversion) to know that persecution was part of being a Christian. They were sure to warn these Thessalonians of the cost of being disciples of Christ (c.f. Matthew 16:24, Luke 14:25-35). Indeed, the affliction did come, and Paul grew concerned about their ability to persevere in their faith. Thus, he sent Timothy to find out about the state of their faith in fear that the tempter might have led them astray. Then Paul’s labor would have been in vain in that the believers wouldn’t have lived much like it at all, being thus unable to transmit their faith to others, making the Thessalonican church a dying entity.
6But now that Timothy has come to us from you, and has brought us good news of your faith and love, and that you always think kindly of us, longing to see us just as we also long to see you,
7for this reason, brethren, in all our distress and affliction we were comforted about you through your faith;
8for now we really live, if you stand firm in the Lord.
Timothy went to them and returned, bringing great news to Paul and Silvanus’ ears that these believers had indeed remained faithful and caring for others. It was even evident that they had been thinking of Paul, Timothy, and Silvanus, wishing to be able to see them again. This brought great comfort to these men of God even while they were in distress, and it gave them great encouragement in the Lord to continue on with great joy in preaching the Word. To know that a spiritual seed has truly taken root and stood the test of trials is greatly encouraging to those who have poured their lives into others. When these stand firm, what a blessing it is.
9For what thanks can we render to God for you in return for all the joy with which we rejoice before our God on your account,
10as we night and day keep praying most earnestly that we may see your face, and may complete what is lacking in your faith?
Their gratitude is overflowing in light of the fact that they have so much joy in hearing of the faithfulness of the Thessalonians. They desire earnestly to see them again so that they can teach them more and help them to grow in their faith. There is more that they want to say and more truth they wish to communicate, but they haven’t been able to do so in person yet, except for Timothy.
11Now may our God and Father Himself and Jesus our Lord direct our way to you;
12and may the Lord cause you to increase and abound in love for one another, and for all people, just as we also do for you;
13so that He may establish your hearts without blame in holiness before our God and Father at the coming of our Lord Jesus with all His saints.
Paul, Timothy, and Silvanus’ prayer is that God and Christ will direct their way to them so that they can see them again. It is remarkable how much these spiritual fathers care about their spiritual children. They have invested their lives for the purpose of spreading the gospel, and to see its fruition is of the utmost reward to them. They pray that the Thessalonians will abound in love for one another and for all people, and their example is surely one to be imitated. They want these believers to grow in holiness and to be without blame at the coming of Christ with all His saints (presumably those who have died in Christ prior to the rapture who are then met with those yet alive at the rapture- see 1 Thessalonians 4:14-17).