To answer your good question, it would be good to read Philippians 4:15-19, “Now ye Philippians know also, that in the beginning of the gospel, when I departed from Macedonia, no church communicated with me as concerning giving and receiving, but ye only. For even in Thessalonica ye sent once and again unto my necessity. Not because I desire a gift: but I desire fruit that may abound to your account. But I have all, and abound: I am full, having received of Epaphroditus the things which were sent from you, an odour of a sweet smell, a sacrifice acceptable, wellpleasing to God. But my God shall supply all your need according to his riches in glory by Christ Jesus.”

In this letter to the Philippians, Paul is showing them how the Lord had faithfully provided for all his needs.  By his own admission, there had been a time when no church ministered to the physical needs of this apostle, except for these faithful Philippians.  They had sent ministry to him while he was in Thessalonica…more than once.  While laboring among the saints in Thessalonica, he was supported partly by working with his hands, and partly by the contributions sent him from Philippi.  We read in 1 Thessalonians 2:9, “For ye remember, brethren, our labour and travail: for labouring night and day, because we would not be chargeable unto any of you, we preached unto you the gospel of God.”  (Acts 18:1-3 shows us that Paul was a tentmaker by trade.)

It is such a blessing to notice that Paul’s concern was not in receiving funds for his physical needs, but that the saints might be blessed of the Lord by their faithful provision to him.  Paul assures the Philippians that he had been fully ministered to by their generosity sent to him by their brother, Epaphroditus.  This generosity was a sacrifice that honored the Lord; indeed it was ‘wellpleasing’ to God.  This attitude in giving shows these people gave to the Lord by ministering to Paul.  We read in 2 Corinthians 9:6-8, “But this I say, He which soweth sparingly shall reap also sparingly; and he which soweth bountifully shall reap also bountifully. Every man according as he purposeth in his heart, so let him give; not grudgingly, or of necessity: for God loveth a cheerful giver. And God is able to make all grace abound toward you; that ye, always having all sufficiency in all things, may abound to every good work.”  It honors the Lord when we give to Him with a cheerful heart.  The amount of the money we give is not so important.  It is the attitude in our giving that concerns the Lord. 

Then, Paul made the remark you asked about.  He said, “But my God shall supply all your need according to his riches in glory by Christ Jesus.” (Verse 19).  Paul calls God here “my God,” to imply that God would reward their supply to him, God’s servant, by fully supplying their every need, even as they had fully supplied his need. It was as if Paul was saying that His God would fully repay them, even though he, Paul, could not. Of course, they served the same God, but Paul was speaking experimentally of how God…His God…used these Philippians to supply his needs.  It was in that same personal and experimental way that Paul wrote in Philippians 1:3, “I thank MY GOD upon every remembrance of you.”

As he continues to write in chapter 4, we see that Paul referred to OUR FATHER in verse 20, and OUR LORD JESUS CHRIST in verse 23.   Indeed, we who know the Lord Jesus Christ as our savior are ONE with all those throughout the world who know Him.  (CC)  (692.6)