Paul continues to express amazement at the fruit in the lives of these believers. We might now take it for granted that we are to support gospel ministers. But that knowledge may be nascent in that early church.
In this verse, Paul calls it a good work. He sees God at work in the life of this church, so that without prompting, they had the spiritual insight to provide support for Paul, a gospel preacher. He said no other church had the same relationship with him.
Philippians 4:15-16: And you Philippians also know that at the beginning of my gospel ministry, when I left Macedonia, not one church participated with me in this matter of giving and receiving except you alone. For even in Thessalonica on more than one occasion you sent something for my need.
It was clearly the Holy Spirit at work, helping the people to see beyond their immediate needs to the needs of others.
Paul also introduces a day called the Day of Christ Jesus. This is an echo of the recurrent refrain in the Old Testament about the Day of the Lord:
An epochal time that upends everything. Something like the end of the world as we knew it, but unlike any we can conceive, rather the end of the things from God's point of view, where God Himself will take over the reins to rule, from which there would be no turning back or reversal. A day that would mark both the end and the beginning on a cosmic scale. It was spoken of in the Old Testament, and the New Testament revealed Christ as the focal point.
In this focus verse, Paul acknowledges both that God is at work in them and that there is still a long way to go. That coming from an apostle carries a lot of weight.
He assures them that good things await them in the day of the Lord. Basically, Jesus is coming back, is what He is saying. And Paul is not lying.
So, rather than telling the people they would have double earthly promotion when they gave him supplies, he pointed their eyes to the second coming. This is instructive.
When the church hears that, how would that make them feel? They would rejoice that when Jesus comes back, they would receive the words Well done, good and faithful servants (Matthew 25:21).
Telling them there is a work in them is also an echo of God describing Himself as the potter (Jeremiah 18:1-6).
Later in this same book, Paul said:
Philippians 2:12-13: So then, my dear friends, just as you have always obeyed, not only in my presence but even more in my absence, continue working out your salvation with fear and trembling. For the one bringing forth in you both the desire and the effort—for the sake of His good pleasure—is God.
Paul tells them that God is working in them, but they also have to work and have an attitude of fear and trembling.
So, the experience of salvation is described here as the beginning of God's work in them. That is part of the multifaceted reality that salvation represents.
We understand that God works in the world, for example, in creation, but the gospel brings forth the reality of God actually working in us. That is different. That is the reality that the death and resurrection of Jesus brought to light.
2 Timothy 1:10: but now made visible through the appearing of our Savior Christ Jesus. He has broken the power of death and brought life and immortality to light through the gospel.
So instead of saying you are saved, you are born again, and you are believers (all of which are true), Paul said God has begun good work in them.
Jesus Himself introduced that concept when He said He and the Father would come and stay in us. The Holy Spirit in us is the reality of Christianity.
John 14:23: Jesus replied, ‘If anyone loves me, he will obey my word, and my Father will love him, and we will come to him and take up residence with him.’”
Let’s go back to the focus verse and behold the glory of God, the glory of the one who, on His own initiative, came to us through the gospel heard, and the gospel preached, the one who chose us in Christ Jesus.
That is good news. There is a work that was begun in this church, and that work was impacting Paul's life miles away.
