The angels are spirits (πνεύματα), that is, spiritual beings, who are without any bodily form whatsoever. To ascribe to them even an ethereal corporeity, as has been done in ancient and modern times, is opposed to Luke 24, 39 and Eph. 6, 12, where corporealness is absolutely denied to spirits. The bodies in which angels from time to time appeared to men, Gen. 18, 2; 19, 1, were only assumed (unio accidentalis). The consumption of food by angels, Gen. 18, 8; 19, 3, must be regarded neither as a natural eating nor as a mere form, but as an act which is as incomprehensible to us as is their temporary assumption of an accidental body. "Homines edunt et bibunt ob egestatem, angeli autem instar flammae consumunt cibum ob potentiam," says J. A. Osiander. The temporary consumption of food like the temporary assumption of a body served to convince the persons to whom they appeared of their true presence. While the angels are πνεύματα, Heb. 1, 14, and God is πνεῦμα, John 4, 24, yet the difference between the angels and God is as vast as is that between the finite creature and the infinite Creator. In contradistinction to the human soul, which is an incomplete spirit (spiritus incompletus), because it has been created as an essential part of man in union with the body, the angels are complete spirits (spiritus completi), because they exist properly as spirits. In contradistinction to God, the infinite Creator, the angels are finite creatures. Like men in this respect they are real persons (υποστάσεις), endowed with intelligence and will, Eph. 3, 10; Heb. 1, 14. Intelligence and will may be predicated also of the fallen angels, Gen. 3 ; Matt. 4, though their mind is perverse and their will depraved. According to Scripture the angels, though being immaterial beings, can nevertheless react upon the bodies of men, Gen. 19, 16; Matt. 4, 5, much in the same manner as the human soul reacts upon the body. Since the angels are intelligent beings, they are capable of becoming acquainted both with one another and with men, Luke 1, 13. 19. Yet they know only as creatures, not as God, so that omniscience and prescience must be denied to them. Whatever knowledge they have they possess a) by virtue of their peculiar nature (2 Sam. 14, 20: natural knowledge); b) by divine revelation (1 Pet. 1, 12; Luke 2, 9-12: revealed knowledge); c) by the beatific vision which they enjoy (Matt. 18,10: beatific knowledge).
Since the angels are spiritual beings, we ascribe to them the following attributes: a) indivisibility, which is due to their incorporeity, or immateriality; b) invisibility, which is a consequence of their spirituality; c) immutability, inasmuch as they are not subject to physical changes: they do not beget, nor are they begotten, Matt. 22, 30; they are neither increased nor diminished; they neither grow old, nor do they decay; and yet they are not absolutely immutable, as God is, but only relatively, or in relation to men; d) immortality, inasmuch as they do not die, though God could annihilate them if He so willed ; e) endless duration, inasmuch as they have a beginning, but not an end, Matt. 18, 10; Jude 6; f) illocality, because as incorporeal beings they occupy no space, but are present at a certain place definitely (in ubi definitivo), though not omnipresently like God, who is everywhere present repletively ,· g) agility or velocity, inasmuch as they are able to change the "where" of their presence with extreme celerity, though without local motion, such as must be predicated of material bodies.
As intelligent beings the angels moreover possess freedom of will nnd, in view of the service for which they are designed, great power. The will of angels is free with respect both to a) immanent acts, such as choosing or rejecting, Jude 6, and b) external acts, such as moving about, speaking, praising God, etc., Luke 2, 9-15. Though the evil angels, being declared enemies of God, cannot but oppose Him, yet they do so of their own free will, John 8, 44. The power of the angels is very great, Ps. 103, 20; 2 Thess. 1, 7; 2 Kings 19, 35; yet it is a finite power, completely under the control of God, Job 1, 12. While their power is superhuman, Ps. 91, 11. 12, or greater than that of man, Luke 11, 21. 22, they are not omnipotent, but subject to God, who rules over them, Dan. 7, 10. While, strictly speaking, only God performs miracles (Ps. 72, 18), nevertheless Holy Scripture teaches that the good angels (2 Kings 19, 35) and the prophets (2 Kings 6, 5. 6) and apostles (Acts 3, 6-12) performed miracles in His name and by His divine power (Ex. 15, 23-25). Whenever the devil performs deeds that to men seem to be miracles (mirabilia seu mira), these are in reality "lying wonders" and "strong delusions," with which God permits him to deceive such as "believe not the truth, but have pleasure in unrighteousness," 2 Thess. 2, 9-12.
The claim that angels once mingled with men by marriage, Gen. 6, 2, is as foolish as it is anti-Scriptural, Matt. 22, 30.