"For it is God who works in you both to will and to do for His good pleasure" (Philippians 2:13). That's God's good pleasure, when the Holy Spirit works in us. The Holy Spirit works in us through the abiding gifts of faith, hope and love (1 Corinthians 13:13).
God works in all who truly believe on the Lord Jesus Christ (1 Corinthians 6:19). God works in us to do his will. God changes our hearts (Romans 2:28-29). That's called regeneration or new birth. He gives us a renewed will with a desire to do his will.
God works in our mind, will, and emotions. He is doing more in us than we can understand. He is always doing more than we ask or think (Ephesians 3:20). God works in our hearts to bring glory to His name. God gives us the ability to do all that pleases him. That includes our ministry gift and power to witness for Christ (Acts 1:8; 1 Peter 4:10-11).
God works in us through the Holy Spirit. He will never leave us nor forsake us (John 14:16-17). Believers are sealed with the Holy Spirit until the day of redemption, at the coming of Christ (Ephesians 1:13, 4:30). God, who began the good work in us, will perform it until the day of Christ (Philippians 1:6; 2:13).