How do we know God will complete His work in us?

In Philippians 1:6, the Apostle Paul assures believers that He who began a good work in them will bring it to completion. This promise is grounded in God's faithfulness and the truth that He is a performing God who is actively involved in the lives of His people. The assurance we have is based upon His mercy, which recurs continually and assures us that He does not abandon His work halfway. Just as He was faithful with David and the promises made to him regarding the kingdom, so He will be faithful with us as we navigate our spiritual journeys.