Walaeus & Mestrezat: we are justified by receiving Christ, not by believing remission already past
Walaeus: the first justifying faith-act is receiving Christ with his merit unto coming remission — not believing remission already past — via will's trust after general assent.
Mestrezat's definition matches: justifying faith is the penitent sinner's refuge to God's mercy in Christ.
Latin
CXXI. Praeterea his adjungimus Antonium Walaeum, qui negat Actum primum fidei quo justificamur, esse actum illum quo creditur remissio peccatorum, sed quo recipitur Christus cum merito ejus, in remissionem peccatorum, non praeteritam, sed sequentem; atque istud non tam per assensum particularem, quam per fiduciam illam voluntatis a generali assensu sequitur. Nec alia potest esse mens Joannis Mestrezatii, cui fides justificans definitur perfugium peccatoris poenitentis ad Dei misericordiam in Christo.