From Sinclair Ferguson’s response to Gerhard Forde in Christian Spirituality: Five Views on Sanctification, 1988), pp 34-35:

Reformed theology is as anxious as Lutheran thought to safeguard grace. It has wrestled very seriously with the whole question of conditions. The term conditions has a certain infelicity about it. But there is a difference between what we might call “conditionality” (which compromises grace by saying, “God will be gracious only if you do X or Y“) and the fact that there are conditions for salvation which arise directly out of the gospel message and do not compromise its graciousness.

These conditions do not render God gracious to us, but are the noncontributory means by which we receive his grace.

Our Lord himself says, “Unless you repent, you too will perish” (Lk 13:3).

Only if we suffer with Christ will we reign with him (Rom 8:17).

“If we confess out sins, he is faithful and just and will forgive us our sins” (1 Jn 1:9).

There is a sine qua non to forgiveness and to justification. They cannot be received apart from faith. This is a biblical condition that does not compromise grace, but arises from it. The important thing is not to deny condition, but to underscore that “It is not faith that saves, but Christ that saves through faith” (B.B. Warfield).”

HT: Jason Taylor