John Calvin used the Latin term “duplex gratia” to describe the tension we often run into when we talk about the doctrines of justification and sanctification (John Calvin, Institutes of the Christian Religion, 3.11.1). Translated “double grace” or “twofold benefit,” this term points to a picture that can help us wrestle with a fundamental theological tension: we must keep the doctrines of justification and sanctification clearly distinct yet inseparable.
Justification refers to the work God has accomplished, completely without our input, by sending his Son, Jesus Christ, to die on the cross. Because Christ paid the penalty for our sins, he serves as our substitute. God declared him guilty and declares us innocent. This is a finished work and is not something to which we can contribute. All we can do is receive this declaration of righteousness by faith as a free gift.
Sanctification refers to the ongoing work of God and people, to make us more like Christ and less sinful. This is a continuous work that will not be completed in this life and in which we cooperate with God. This work progresses over a lifetime, is not instantaneous, and finds greater growth in the lives of some Christians than others. Although it remains an unfinished reality in the life of a believer, no one will arrive in heaven without sanctification.
Calvin’s term can help us process the apparent contradiction between justification and sanctification. In English, we call a house that is divided into two distinct halves a duplex. A duplex is not a single-family dwelling, and yet it remains one building.
We run into trouble in our Christian life when we think of only one half of this theological duplex as describing our entire Christian experience. While it is impossible to emphasize the importance of justification too highly, for instance, it is possible to overemphasize justification to the exclusion of the ongoing reality of sanctification. It is also possible to stress sanctification so strongly as to lose sight of our justification. However, neither justification nor sanctification, by themselves, are adequate to describe the entire Christian life.
In spite of this, many Christians live their lives as if they only reside on one side of the duplex or the other. The trick to the Christian life is this: when someone asks you where you live, simply point to the duplex.
This may appear at first as if I’m suggesting something akin to the man who, when the waitress asked if he was full or needed something else to eat, simply replied, “Yes!” However, these two doctrines complement each other by reflecting the robust teaching of the New Testament regarding our salvation. Because of that, I invite you to embrace the duplex while we explore how justification and sanctification work together as our sermon series continues in the next few weeks.