Under the sacrificial system in the Old Law there was certain criteria for selecting a sacrifice. It would have to usually be a male, free from defect, etc. So, too, for Christians. 2. Christians are to be set apart from the world, dedicated to God. The Greek word here seems to denote an exercise of the intellect.
All Christian service comes from an exercise of the mind in control of the emotions.
This passage envisions a continual, ongoing process of changing the mind into an instrument of service to God. We must continually seek to rid our minds of worldly thoughts and our lives of worldly actions. The only way for us to determine what is right and wrong is to grow closer to God. For I say, through the grace given to me, to everyone who is among you, not to think of himself more highly than he ought to think, but to think soberly, as God has dealt to each one a measure of faith. 5- so we, being many, are one body in Christ, and individually members of one another.