John Calvin on the Christian life:

If we, then, are not our own [cf. 1 Cor. 6:19] but the Lord's, it is clear what error we must flee, and whither we must direct all the acts of our life.

We are not our own: let not our reason nor our will, therefore, sway our plans and deeds. We are not our own: let us therefore not set it as our goal to seek what is expedient for us according to the flesh. We are not our own: in so far as we can, let us therefore forget ourselves and all that is ours.

Conversely, we are God's: let us therefore live for him and die for him. We are God's: let his wisdom and will therefore rule all our actions. We are God's: let all the parts of our life accordingly strive toward him as our only lawful goal [cf. Rom. 14:8; cf. 1 Cor. 6:19]. O, how much has that man profited who, having been taught that he is not his own, has taken away dominion and rule from his own reason that he may yield it to God! For, as consulting our self-interest is the pestilence that most effectively leads to our destruction, so the sole haven of salvation is to be wise in nothing through ourselves but to follow the leading of the Lord alone.

--Calvin, Institutes of the Christian Religion, 3.7.1 (Quoted in John Calvin: A Heart for Devotion, Doctrine and Doxology, ed. Burk Parsons, pp. 6-7)