De Moor IV:43: The Mercy of God
Mercy is also to be referred to Goodness, no less than Grace, from which it hardly differs otherwise than that this includes the Misery of the Object with which it has to do. These two accompany each other; and as Grace exerts itself concerning man as sinner, so that it might grant to him the pardon of sin; so Mercy is exercised concerning man as Miserable because of sin, so that it might relieve his misery.
It denotes an Affection of God, yet not to be conceived in God after the manner of the human Affection, but to be explained θεοπρεπῶς, in a manner suitable for God, in accordance with § 26 of this Chapter. That is, divine Mercy does not include anguish received from the misery of another, as it does indeed in men; but it applies to God only insofar as it denote His prompt and ready will to relieve the miserable without all grief and perturbation.
From this Affection God is not only called אֵ֥ל רַח֖וּם, the merciful God, Exodus 34:6, ὁ Πατὴρ οἰκτίρμων, the merciful Father, Luke 6:36; but also ὁ Πατὴρ τῶν οἰκτιρμῶν, the Father of mercies, 2 Corinthians 1:3, to whom is applicable πολὺ ἔλεος, abundant mercy, 1 Peter 1:3, indeed, who is πλούσιος ἐν ἐλέει, rich in mercy, Ephesians 2:4. This divine Affection of Mercy is quite frequently made known through similitudes, of a Shepherd, caring for his sheep with consummate affection, Isaiah 40:11; thus after the likeness of a Shepherd, who leads the flock to water, the Lord is also able to be considered, Isaiah 49:10, where it expressly occurs under the name of מְרַחֲמָם, one having mercy on them: of a most loving Father, Psalm 103:13: of a most tender Mother, Isaiah 49:15. Hence, just as רַחֲמִים/mercies/compassions is of the same origin with רֶחֶם/womb/uterus, which embraces the fetus with the most tender affection, if רֶחֶם/uterus be not the very root itself (see VRIEMOET’S Adnotationes ad Dicta Classica Veteris Testamenti, part I, chapter VIII, page 298); the affection of Mercy in the most tender manner, with anthropopathic mention made of the stirring of the bowels, is als ascribed to God, Jeremiah 31:20; Hosea 11:8; Luke 1:78, διὰ σπλάγχνα ἐλέους Θεοῦ ἡμῶν, through the bowels of the mercy of our God.
So that the divine Independence might remain in good repair, it is to be observed that Misery is by no means the Cause of this divine Affection, such that God might be moved by some external cause, which is wont to excite this sort of affection in men. God is here moved by His Goodness alone, which does not decline to relieve the miserable; so that mercy might only stand in the manner of a prerequisite quality and condition sine qua non in the object. Hence God by no means shows mercy equally, but has to do with miserable objects with such freedom that divine Mercy is able to exert itself unto salvation, or not, without injury to any, Romans 9:15, 18.
With regard to saving efficacy, it is proper to the Elect, who hence are called σκεύη ἐλέους, vessels of mercy, Romans 9:23; and this Mercy of God is called Special: only in a certain manner is this Affection of God said to be common to reprobates, in which sense, of course, we speak of the General Mercy of God, whereby He helps all creatures afflicted with neediness and misery, which General Mercy concerns τὰ βιωτικὰ and matters of this life; in this sense it is read in Psalm 145:9,וְ֜רַחֲמָ֗יו עַל־כָּל־מַעֲשָֽׂיו׃, and His tender mercies are over all His works: thus God is said to be χρηστός ἐπὶ τοὺς ἀχαρίστους καὶ πονηρούς, kind unto the unthankful and to the evil, Luke 6:35, where χρηστός/kind in verse 35 and οἰκτίρμονες/merciful in verse 36 are used interchangeably. This more common Mercy of God the Ultimate Good is also known by nature: but, although Vindictive Justice is also made known by nature, Special Mercy, whereby God is πλούσιος ἐν ἐλέει, rich in mercy, unto the σκεύη ἐλέους, vessels of mercy, is revealed only in the Gospel.
 That is, without which not, or necessary.
 See, for example, 1 Corinthians 6:3: “Know ye not that we shall judge angels? how much more things that pertain to this life (μήτι γε βιωτικά)?”