Assurance

And I am sure of this, that he who began a good work in you will bring it to completion at the day of Jesus Christ. (Philippians 1:6 ESV)

Paul's joy at the thought of the Philippians being participants in the fellowship of the gospel leads him to make an emphatic statement. He is sure. He is certain. He is convinced that his fellows in the gospel will be with him in that fellowship until the culmination of Christ's redemptive work. How can he be so sure? After all, they are human. They are fallible. Paul, of all people, knows the weakness of human flesh. It is Paul who has spelled out for us, in his epistles, the doctrines of human depravity and original sin.

as it is written: “None is righteous, no, not one; no one understands; no one seeks for God. All have turned aside; together they have become worthless; no one does good, not even one.” (Romans 3:10-12 ESV) 

for all have sinned and fall short of the glory of God, (Romans 3:23 ESV) 

For as in Adam all die, . . . (1 Corinthians 15:22 ESV)

So if the Philippians are incapable of saving themselves, how can Paul be sure that those same Philippians will be fully and finally saved at the day of Christ? Or, to put it another way, how can he be sure that when "the roll is called up yonder" they'll be there?

And make no mistake. Paul is assured of their salvation. He is confident. He is certain. He says so quite clearly.

The answer to the question is simple. The work is not theirs. The work is God's. Salvation is God's work from beginning to end. It is all of grace.

Like you, I am very human. I have often begun projects that I never finished. Sometimes I get tired of a project. Sometimes I decide a project is more trouble than it's worth. Sometimes I fail to count the cost. Sometimes I just lose interest. Sometimes I find I am simply unable to complete a task.

But not God. God is not a man that he should change his mind. He never makes an error in judgment. He never has to re-think anything. He never lacks what it takes to finish. When he starts something you can be sure it is worth starting and If it is worth starting it is worth finishing.

So if God has begun a work of grace in you, he will complete it. He always does what he intends.

all the inhabitants of the earth are accounted as nothing,  

and he does according to his will among the host of heaven  

and among the inhabitants of the earth;  

and none can stay his hand  

or say to him, "What have you done?” 

(Daniel 4:35 ESV)

Paul said that to assure them. We need to be reminded that God is faithful--even when we are not. Has God begun a good work in you? Then trust him that he will not let you go.