By Christ purchasing redemption, two things are intended, his satisfaction, and his merit. All is done by the price that Christ lays down, which does two things: it pays our debt, and so it satisfies; it procures our title to happiness, and so it merits. The satisfaction of Christ is to free us from misery, and the merit of Christ is to purchase happiness for us.
The Works of Jonathan Edwards Vol. 1 (Peabody, MA; Hendrickson Publishers, Inc; 2007) p. 574. A History of the Work of Redemption. Period 2: From Christ’s Incarnation to His Resurrection. Part 2: The Purchase of Redemption.