Article — Prümmer, Manuale Theologiae Moralis
Article VII. On the Tempting of God
526. Preliminary note. Thus far there has been discussion of sins against religion by excess; now irreligion strictly so called must be treated, which is opposed to religion by defect, insofar as from its own nature it contains something contrary to divine worship, namely, irreverence and contumely. Certainly superstition and its species also inflict irreverence upon God, but not so immediately and directly as irreligion strictly so called, which is directed immediately either against God Himself or against sacred things (at least if one excepts idolatry). Against God are temptation and blasphemy; against sacred things are sacrilege and simony. Each must be treated separately.
527. Notion. The tempting of God is a word or deed by which someone explores whether God has or exercises some perfection, for example, knowledge, power, or mercy.802 Therefore, to tempt God is nothing other than to make a trial, without sufficient cause, of some divine attribute, or to expect an unusual manifestation of God.
Division. The tempting of God is distinguished as formal (express, explicit) and virtual (interpretative).
The former is present if someone, through those things which he does or says, expressly intends to explore some perfection of God or His will. In this sense we read concerning the Israelites: "They tempted the Lord, saying: Is the Lord among us or not?"803 And in the Psalms it is said: "They tempted God in their hearts, ... can God furnish a table in the desert?"804 Such formal temptation is also present if someone, doubting God's power, asks a miracle from Him; or if someone casts himself into a well with the intention of testing whether God wills to save him miraculously.
The latter temptation is present when someone does not indeed directly intend to make a trial of God, but nevertheless does or omits something useful for nothing else than proving either God's power or His goodness; as if someone does not indeed doubt God's power and goodness, but frivolously exposes himself to danger of death, hoping for God's miraculous assistance. The former temptation, namely, formal temptation, is accustomed to proceed from infidelity or at least from doubt concerning some perfection of God; the latter temptation, namely, virtual temptation, arises for the most part from presumption or excessive confidence. To explain the nature of this temptation, the Angelic Doctor writes:805 "He tempteth God as it were interpretatively who, although he does not intend to make trial of God, nevertheless asks or does something which is useful for nothing else than proving God's power or goodness or knowledge. Thus, when someone makes a horse run in order to escape enemies, this is not to make trial of the horse; but if he makes the horse run without any utility, this seems to be nothing other than to make trial of the horse's speed. Therefore, when someone for some necessity or utility commits himself to divine assistance in his petitions or deeds, this is not to tempt God; for it is said: 'Since we know not what we ought to do, we have only this left, that we direct our eyes to thee.'806 But when this is done without utility and necessity, this is to tempt God interpretatively."
802 Cf. S. theol. 2, 2, q. 97, a. 1; St. Alphonsus, Theol. mor. l. 3, n. 29.
804 Ps. 77:18ff.
805 S. theol. 2, 2, q. 97, a. 1.
806 2 Chron. 20:12.
528. Moral malice. Formal temptation of God is a mortal sin in its whole genus; interpretative temptation, however, is a mortal sin from its genus.
Explanation. Formal temptation includes a twofold grave sin, namely, of infidelity and of grave irreligion; for it supposes at least a doubt concerning some perfection of God, and then expects God miraculously to produce a vain and useless effect, which certainly is very irreverent toward His majesty. Hence Christ also indignantly responded to the devil asking a miracle: "Thou shalt not tempt the Lord thy God."807
Interpretative temptation also is directly contrary to the virtue of religion and therefore is a mortal sin from its genus. Added to this is that it is often joined with a grave injury to charity toward oneself, as if someone casts himself into a well with danger to his life, hoping for miraculous salvation. For the most part, however, such interpretative temptation is only a light sin, because only light matter and a light danger are involved. Hence, for example, one sins lightly who in a light illness refuses to take medicine and expects health from God. Whether a cleric sins gravely who through negligence approaches the pulpit wholly unprepared, hoping for special assistance from God, is to be weighed not only from the tempting of God committed, but especially from the scandal which sermons of this kind, not prepared, are accustomed to cause if the hearers perceive the negligence of the sacred orator.
807 Matt. 4:7.