"Being confident of this very thing, that He which hath begun a good work in you will perform it until the day of Jesus Christ."
Paul the Apostle was a master wordsmith, and it seems that he was fond of long and complex sentences. Our verse for today is taken from the middle of one of those marathon sentences (verses 3-7). Although we are primarily looking at verse 6, I trust that we will not wrest the meaning from the sentence.
“I am sure that the good work God began in you will continue until He completes it on the day when Jesus Christ comes again” (Philippians 1:6,  HSB).
“Being confident of this very thing.”
Self-confidence can be a scary thing and is not what is essential in the believer here, but confidence in who God is and what He does is vital for each child of God. This directly impacts our relationship with Jesus Christ. Our trust, faith, belief, and confidence are in Him! He will bring it to pass!
“Being confident … since I am confident”  (Vincent).
“Great confidence gripped the apostle as he thought and prayed for the Philippians. The perfect tense of the Greek word translated being confident indicates that Paul had come to a settled conviction earlier and that he still was confident it was true”  (BKC).
It is God who saves us. We cannot in any way provide salvation for ourselves. Since God has begun this great work in us, God will finish it. In the present, our souls are saved, but we wait impatiently for our new bodies to be given to us in the future.
“And not only they but ourselves also, which have the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption, to wit, the redemption of our body” (Romans 8:23).
“Paul is confident as he prays, with a confidence not based on the Philippians’ own abilities or past achievements, but on the power and love of God and because God can be relied upon to bring what He begins to completion”  (NBC).
“That He which hath begun a good work in you.”
God’s incredible mercy and grace brought us to a saving knowledge of Jesus. He has provided us with the intelligence to understand and the faith to believe the Gospel message (v. 6). It is God that has begun this good work in us.
“A Good Work”
“It was indeed a good work begun in the Philippians and in all believers. “The work of grace has its root in the divine goodness of the Father, it is planted by the self-denying goodness of the Son, and it is daily watered by the goodness of the Holy Spirit; it springs from good and leads to good, and so is altogether good”  (Spurgeon).
Everything God does in us and for us is good. He is good, and His work is good!
“And we know that all things work together for good to them that love God, to them who are the called according to his purpose” (Romans 8:28).
“Will perform it until the day of Jesus Christ.”
He “Will Perform It”
“Paul’s confidence in prayer resulted from the principle that God finishes what he begins, and the fact that the Philippians demonstrated their Christian character by joining in the support of the gospel work”  (CSB).
Try to imagine God starting something that He does not finish. It’s impossible; we cannot! That is totally out of character for our God, especially when He promises that He will complete it! He works with each believer while they are here “at home in the body.”
“For it is God which worketh in you both to will and to do of his good pleasure” (Philippians 2:13).
“For we are His workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them” (Ephesians 2:10).
“Now the God of peace, that brought again from the dead our Lord Jesus, that great shepherd of the sheep, through the blood of the everlasting covenant, Make you perfect in every good work to do His will, working in you that which is well-pleasing in his sight, through Jesus Christ; to whom be glory forever and ever. Amen” (Hebrews 13:20-21).
God not finishing what He has begun is an oxymoron.
“Where is there an instance of God’s beginning any work and leaving it incomplete? Show me for once a world abandoned and thrown aside half formed; show me a universe cast off from the Great Potter’s wheel, with the design in outline, the clay half hardened, and the form unshapely from incompleteness”  (Spurgeon)
Paul had no doubts about God finishing His work.
“What was he so confident and sure of? It was that God would most certainly continue on to completion the good work He had begun in them. That good work was their salvation. It may also have included their fellowship and sharing of their bounties with Paul”  (BKC).
“When we see that God has begun a good work in people’s lives, we can be sure that it is his purpose to continue—that can always be our confidence in praying for our fellow Christians”  (NBC).
“Until The Day of Jesus Christ”
Yes, there is a wonderful day coming when God will complete in us that work He has begun. It is the day when we see Jesus Christ.
“Behold, what manner of love the Father hath bestowed upon us, that we should be called the sons of God: therefore, the world knoweth us not, because it knew Him not. Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when He shall appear, we shall be like Him; for we shall see Him as He is. And every man that hath this hope in him purifieth himself, even as He is pure” (1 John 3:1-3).
Dear Lord Jesus, we long for your coming and completing your work in us!
Quote: “He which testifieth these things saith, Surely I come quickly. Amen. Even so, come, Lord Jesus” (Revelation 22:20).
 HSB is the Harvest Study Bible from Harvest Ministries in Guam.
 Marvin Richardson Vincent, Word Studies in the New Testament, vol. 3 (New York: Charles Scribner’s Sons, 1887), 417.
 BKC, Robert P. Lightner, “Philippians,” in The Bible Knowledge Commentary: An Exposition of the Scriptures, ed. J. F. Walvoord and R. B. Zuck, vol. 2 (Wheaton, IL: Victor Books, 1985), 649.
 NBC, Francis Foulkes, “Philippians,” in New Bible Commentary: 21st Century Edition, ed. D. A. Carson et al., 4th ed. (Leicester, England; Downers Grove, IL: Inter-Varsity Press, 1994), 1250.
 Spurgeon’s quote is borrowed from EWC – David Guzik. Enduring Word Commentary, the electronic version in eSword.
 CSB, Richard R. Melick Jr., “Philippians,” in CSB Study Bible: Notes, ed. Edwin A. Blum and Trevin Wax (Nashville, TN: Holman Bible Publishers, 2017), 1884.
 Spurgeon’s quote is borrowed from EWC, ibid.
 BKC, ibid.
 NBC, ibid.