Philippians 1:6

being confident of this, that he who began a good work in you will carry it on to completion until the day of Christ Jesus.

(v6, NIV)

Paul is still talking to those who are followers of the Lord Jesus Christ. These people are ones who are also called saints. There is a work that occurs within those who live their life for Jesus. This work is done and started by God and this good work will be carried to completion. God finishes what he starts. Sometimes we will start a project and never finish it. Some of us will set out to build something or to accomplish something only to give up a while later. For instance, there are a few times when I have set out to read the entire bible. However, I am sad to inform you that I have never read the bible from cover to cover, thus I have failed in those goals. Fortunately, God doesn't just start something and then stop halfway through. God finishes what he starts. God's work that began in those who are his true adopted children will be completed. You don't have to question this, it will be done. God keeps his own. However, the real question is whether you are one of his own. Do not absent-mindedly put your faith into a whimsical assurance of a half-hearted confession you made 10 years ago. As emotional as it may have been, was it a true repentance and turning from your ways and true acceptance and declaration of the Lord Jesus Christ? Do not be deceived.

What does continuing a good work in you mean? Well, if God did begin a good work in you, your coming back to God will make sure of that. Jonah tried to run away, but God would not let him.

What's interesting is that God is the one who began the work and it is God who will carry it until completion. It is not us who does the work, but God does the work. This work that is brought to completion is not by us but by God who begins, carries it through, and completes it.