Our Scripture reading today is Romans 12:1-2. 
"I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service. And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God."
We learned last night at the mission's conference of the importance of giving ourselves first.  2 Corinthians 8:5, "And this they did, not as we hoped, but first gave their own selves to the Lord, and unto us by the will of God."  While it is important that we give of our finances that God has provided for us, it is most important that God has US.  
In our text this morning, a very similar truth is presented by the Apostle Paul.  The life that God has given to us is to be presented back to Him for His service.  How can we determine what we will do with our lives without even considering what God's will is for our lives?  Unfortunately this happens far too often in the family of God.  There are adults today working securely that when they were teenagers, God was calling them into ministry.  What happened?  There was an unwillingness of the young person or his or her parents to allow them to surrender to God's call to the ministry.  In no way am I saying it is wrong to work securely.  Whether a secular worker or a missionary in Germany, God deserves to have US.  It is our reasonable service!