Why is it important for Christians to focus on the eternal rather than temporary earthly matters?

Newton emphasizes that Christians are ultimately strangers and pilgrims in this world, and their true citizenship lies in heaven. In light of eternity, the busyness of earthly life and its issues will seem trivial when faced with the eternal realities. Matthew 6:19-21 advises believers to store up treasures in heaven, redirecting their hearts from the temporal to the everlasting. Christians are called to be diligent in their spiritual callings, knowing that fulfilling their roles in the kingdom of God has eternal significance, particularly as they prepare for the return of Christ.