There are two senses to the word condition in Reformed (covenant) theology. Sometimes they were used under the same topics in both senses. It was expected that the reader would discern the distinction but given that, in the confessional Reformed world, we are still recovering classical Reformed theology after about a century of overlooking and ignoring other key aspects (e.g., the pactum salutis, the covenant of works) it should not surprise us that it we need also to re-learn this distinction too.
When we use the word “condition,” the first sense that probably comes to mind, in English usage, is the first definition offered by the Oxford English Dictionary: “convention, stipulation, proviso.” There is another sense to the word, however, as it was used by our theologians that might be hidden to us because we might not appreciate its roots and background. That is the sense “mode of being, state, posture, nature” (which is the second major definition given by the OED).
Our theologians used the Latin noun conditio in both senses just as we use condition. Sometimes they used it in both senses in proximity to each other and so do we. Thus, some clarification is in order. I have tried to express the distinction this way: 1) On the basis of or through; 2) Is. In the contemporary discussion about the necessity of sanctification in salvation this distinction has not always been observed or perhaps, in some quarters, it is rejected. In either case we should recover it so that we may have both a vigorous, biblical, evangelical (in the best sense), Protestant, confessional doctrine of salvation (justification, sanctification, and deliverance from the wrath to come).
When our writers spoke of antecedent and consequent conditions they were making this distinction between stipulation that must be fulfilled and a consequent state or mode of being. In the 16th century, however, as our writers were working out our covenant theology, they spoke of stipulations in the first sense and “re-stipulations” in the second. In the late 17th century, Herman Witsius distinguished between antecedent (prior) andconsequent conditions.
The antecedent condition of the covenant of works was the perfect obedience of a federal head. Adam was the federal representative or substitute of all humanity and he was charged with obeying on our behalf. He did not. Christ is the Last Adam, who obeyed on behalf of all the elect. We receive the benefit of Christ’s satisfaction of the antecedent condition of the covenant of works (obedience) by grace alone (sola gratia), through faith alone (sola fide). Those who are thus united to Christ by the Spirit, sola fide, necessarily produce the fruit of of their salvation in good works as evidence of their salvation.
This fruit is said to be a consequent condition but here condition has a different meaning. It has the sense of “state” or “mode of being.” It is the case that believers, renewed by the Spirit, are being sanctified and shall produce good works but they do not serve the same function as the good works did in the covenant of works nor do they serve the same function as faith does in the covenant of grace. Rather, they are a logically and morally necessary consequence of God’s grace.
Here are two examples of the two sense of conditio in Francis Turretin’s Institutes of Elenctic Theology (1679).