1. Enemies of the cross (17-19)
Paul loved the cross of Jesus because through the cross he knew God's love and his grace of forgiveness. Paul set an example to follow. He warns us not to live as enemies of the cross. Self-indulgence is an enemy of the cross. To allow one's mind to be occupied with thoughts and plans of how to indulge one's appetites makes one an enemy of the cross. Paul says that the destiny of enemies of the cross is destruction.
2. Citizens of heaven (20-21)
Citizens of heaven are those who eagerly await a Savior from there--Jesus. If we set our minds on Jesus and put our hope in him, he will work in us by his almighty power to mold us into his image and prepare us for our heavenly home.
Application: Lord, come and rule my heart and thoughts. Help me not to think about food or clothes or cars or computers, or spend too much time in front of the TV. Help me to fix my thoughts on Jesus, and pray for his work and his people.
One Word: Live as a citizen of heaven