Zac Poonen emphasizes the significance of the phrase 'Thine is the kingdom, the power, and the glory forever' from the Lord's Prayer, explaining that it reflects God's ultimate authority, power, and the glory He deserves. He urges believers to submit to God's government in all aspects of life, including speech, finances, and time management, highlighting that true joy and peace come from accepting His authority. Poonen also stresses the importance of recognizing God's power to overcome fear and sinful habits, and the necessity of giving thanks and glory to God for all achievements, as everything we have is a result of His grace.