From Hodge’s Systematic Theology:

Propitious and loving are not convertible terms. God is love. He loved us while sinners, and before satisfaction was rendered. Satisfaction or expiation does not awaken love in the divine mind. It only renders it consistent with his justice that God should exercise his love towards transgressors of his law. This is expressed by the Greek verb ἱλάσκομαι, propitium facio. “To reconcile oneself to any one by expiation.” That by which this reconciliation is effected is called ἱλασμός or ἱλαστήριον. The effect produced is that God is ἵλαος. God is good to all, full of pity and compassion to all, even to the chief of sinners. But he is ἵλαος only to those for whose sins an expiation has been made. That is, according to the Old Testament usage, “whose sins are covered.” “To cover sin,” כַּפֵּר, is never used to express the idea of moral purification, or sanctification, but always that of expiation. The means by which sin is said to be covered, is not reformation, or good works, but blood, vicarious satisfaction.

~Systematic Theology 3.6.3