3 For through the grace given to me I say to everyone among you not to think more highly of himself than he ought to think; but to think so as to have sound judgment, as God has allotted to each a measure of faith. 4 For just as we have many members in one body and all the members do not have the same function, 5 so we, who are many, are one body in Christ, and individually members one of another. Romans 12:3-8 (NASB) (Read verses 6-8 on the site)
Born Again believers have a duty to God to give themselves unto Him completely as we saw in my post The Believer’s Supreme Act of Spiritual Worship. It is through becoming a living sacrifice that the believer’s sanctification precedes to the level of surrender. This process takes place as the Holy Spirit renovates the minds of these believers as they submit more and more to the Word of God in all parts of their lives. Those who are on this path of spiritual growth become ready for service.