And we shall deal first with the justification of the sinner in the sight of God, as this is easily the foremost locus in theology, and for us the one most salutary. And if this locus is suppressed, falsified, or overturned, it would not be possible to keep the purity of the teaching in other loci or to maintain a true Church. Now the main point and basis of this locus is the fact that a merciful and just God pardons the sins of believers through the righteousness of his Son and causes then to be saved.

Synopsis of a Purer Theology, Vol. 2, 384.