Three truths are critical to believers as "citizens of heaven." Paul was persuaded (confident) that "He who began a good work in you will carry it on to completion until the day of Jesus Christ." Philippians 1:6
1) God initiated our relationship in Him and the moral and spiritual changes that occur in our lives since we came to Christ ("He who began"). We are not the author of the life of Christ which is being lived out daily in us. We are not the initiators of finding joy amidst the challenges and problems of life - God is the One who has begun the changes in us that bring us fulfillment and that bring Him pleasure. We cannot change to be like Christ on our own - He is our power and strength.
2) God continues to transform us into the likeness of Jesus Christ ("will carry it on to completion"). He does not give birth to us as His children and then leave us to struggle alone with how to live this new-found freedom in Christ. He gives His Holy Spirit, His Word, and fellow believers to help us and encourage us when we are tempted to focus on the problems of today rather than His transforming power.
3) He makes us people of the future. "Until the day" speaks of Christ's coming again. Our glorious future has begun already in the present. To lose our future orientation - "straining toward what is ahead, toward the goal to win the prize for which God has called us heavenward" (Philippians 3:13-14) is to lose joy, hope, and motivation.
Paul reminds us that even in the midst of present difficulties, God in Christ both guarantees our future and blesses us in our present - whatever it is.
Focused on the future in the present ~ Bob