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. Philippians 1:6 (NIV)
As long as it is God who started that which concerns you, there’s no doubt at all and you can rest assured that its completion is already ensured.
God has never started on anything He never completed.
He’s the Author and Finisher. He is the pioneer and perfector.
He’s the author and finisher of life. He’s the pioneer and perfector of faith. He’s the author and finisher of salvation.
He did not start us on the path of faith, salvation and eternal life to leave us hanging in the middle. He finished everything He has called us to.
We are not called to work on and complete the faith, salvation, and life that God called us to. We are called to walk in the already started and already completed by God faith, salvation and life.
The Scripture that says we should work out our salvation (Philippians 2:12) doesn’t mean we should add our part and effort to improve on what God has done.
It says work out – meaning let that already perfect salvation that’s already in you, flow and come out throughout your mind, body and everything you do. It means allow the already complete salvation that you already have received dominate and govern your life and conduct.
So then to say that God completes what he has started means He works with and in you not to perfect you or what concerns you but rather to help you see, accept, be fully persuaded and therefore walk out and live out the perfect faith, salvation and life He’s put in you.