The law of the Lord is the best and most suitable instruction for the proper ordering of our lives. Nevertheless, it seemed good to our heavenly teacher to conform us by an even more precise rule than what’s given in the precepts of the law. This is the sum of that rule: It is the duty of believers to present their bodies as living sacrifices, holy and acceptable to God. And in this consists genuine worship of Him. From this rule is derived the exhortation that believers not be conformed to this world, but be transformed by the renewal of their minds, so that by testing they may discern what is the will of God.
I appeal to you therefore, brothers, by the mercies of God, to present your bodies as a living sacrifice, holy and acceptable unto God, which is your spiritual worship. Do not be conformed to this world, but be transformed by the renewal of your mind, that by testing you may discern what is the will of God, what is good and acceptable and perfect. (Romans 12:1-2, ESV)
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If we are not our own but the Lord’s, it’s clear what errors we must flee, and what we must direct our whole lives toward. We are not our own; therefore, neither our reason nor our will should dominate our plans and actions. We are not our own; therefore, let us not make the gratification of our flesh our end. We are not our own; therefore, as much as possible, let us forget ourselves and our own interests.
Rather, we are God’s. Therefore, let us live and die to Him. We are God’s. Therefore, let His wisdom and His will govern all our actions. We are God’s. Therefore, let us—in every way in all our lives—run to Him as our only proper end. How far has he progressed who’s been taught that he is not his own—who’s taken rule and dominion away from his own reason and entrusted them to God. For the plague of submitting to our own rule leads us straight to ruin, but the surest way to safety is neither to know nor to want anything on our own, but simply to follow the leading of the Lord.
–John Calvin in A Little Book on the Christian Life, edited and translated by Aaron Clay Denlinger and Burk Parsons, Reformation Trust Publishing, Sanford, Florida (2017), 21-23.