What is justification?

Justification is an act of God’s free grace unto sinners,^[1] in which he pardoneth all their sins, accepteth and accounteth their persons righteous in his sight;^[2] not for any thing wrought in them, or done by them,^[3] but only for the perfect obedience and full satisfaction of Christ, by God imputed to them,^[4] and received by faith alone.^[5]