Romans 14:8-9 (NIV)
If we live, we live for the Lord; and if we die, we die for the Lord. So, whether we live or die, we belong to the Lord. 9 For this very reason, Christ died and returned to life so that he might be the Lord of both the dead and the living.
I also wanted to include another favorite passage that I think compliments the Romans verses quite nicely. They provide a practical prayer for direction each day:
Let the morning bring me word of your unfailing love, for I have put my trust in you. Show me the way I should go, for to you I entrust my life.