Reading excerpts from St Irenaeus on the nature of man, the following verse from St Paul showed up:
"And the God of peace Himself sanctify you wholly; and may your spirit and soul and body be preserved entire, without blame at the coming of our Lord Jesus Christ." (1 Thess 5:23)
The author of the excerpt collection is unable to determine whether "spirit" here refers to a spirit of man which constitutes his nature or to the Spirit of God by which he shares in the divine life. Here are some other Fathers on this question:
John Chrysostom, Homily 11 on 1 Thessalonians:
Sanctify you wholly,he says, and may
your spirit and soul and body be preserved entire, without blame at the coming of our Lord Jesus Christ.What does he here call the spirit? The gift of grace. For if we depart hence having our lamps bright, we shall enter into the bridechamber. But if they are quenched, it will not be so. For this reason he says
your spirit.For if that remains pure, the other remains also.
And soul and body,he says. For neither the one nor the other then admits anything evil.
Fourth Council of Constantinople, Canon 11 (some make spirit and soul two different souls):
While the Old and New Testaments teach that man has one rational and intellectual soul, and this is the teaching also of all the fathers and doctors of the Church, some persons, nevertheless, blasphemously maintain that he has two souls. This holy and general council, therefore, anathematizes the authors and adherents of that false teaching. Anyone presuming to act contrary to the decision of this great council, shall be anathematized and cut off from the faith and society of Christians.
Irenaeus, Against Heresies 5.6:
Now the soul and the spirit are certainly a part of the man, but certainly not the man; for the perfect man consists in the commingling and the union of the soul receiving the spirit of the Father, and the admixture of that fleshly nature which was moulded after the image of God.
http://www.newadvent.org/fathers/0103506.htm (the first paragraph has more explanation)
Thomas Aquinas, Commentary on 1 Thessalonians:
On account of these words, certain people maintained that the spirit in man is one element and the soul another, thus positing two souls in man, that is, one which animates the body and another which carries on the function of reasoning. These opinions are rejected in the Church’s teaching. For it should be realized that these two elements [which are really one] do not differ essentially, but only by reason of the powers present in them. There are certain powers in our soul which are linked to bodily organs, such as the powers of the sensitive part of the soul. And there are other powers which are not linked to bodily organs, but function apart from the body, insofar as they are the powers of the intellectual part of the soul. The latter powers are regarded as spiritual powers in that they are immaterial and separated in some manner from the body in that they are not functions of the body but are referred to as the mind. “Be renewed in the spirit of your minds” (Eph. 4:23). Yet it is called the soul insofar as it animates the body, for this is proper to it. Paul speaks here in a specific sense.
It now remains for me to show how it is that while the designation spirit is rightly predicated of a part of the soul, not the whole of it—even as the apostle says,
Your whole spirit, and soul, and body;1 Thessalonians 5:23 or, according to the much more expressive statement in the Book of Job,
You will separate my soul from my spirit,Job 7:15 — yet the whole soul is also called by this name; although this question seems to be much more a question of names than of things. For since it is certainly a fact that there is a something in the soul which is properly called
spirit,while (this being left out of question) it is also designated with equal propriety
soul,our present contention is not about the things themselves; mainly because I on my side certainly admit, and you on your part say the same, that that is properly called spirit by which we reason and understand, and yet that these things are distinguishingly designated, as the apostle says
your whole spirit, and soul, and body.This spirit, however, the same apostle appears also to describe as mind; as when he says,
So then with the mind I serve the law of God, but with the flesh the law of sin.Romans 7:25 Now the meaning of this is precisely what he expresses in another passage thus:
For the flesh lusts against the spirit, and the spirit against the flesh.Galatians 5:17 What he designates mind in the former place, he must be understood to call spirit in the latter passage. Not as you interpret the statement,
The whole mind is meant, which consists of soul and spirit,— a view which I know not where you obtained. By our
mind,indeed, we usually understand nothing but our rational and intellectual faculty; and thus, when the apostle says,
Be renewed in the spirit of your mind,Ephesians 4:23 what else does he mean than, Be renewed in your mind?
The spirit of the mindis, accordingly, nothing else than the mind, just as
the body of the fleshis nothing but the flesh; thus it is written,
In putting off the body of the flesh,Colossians 2:11 where the apostle calls the flesh
the body of the flesh.He designates it, indeed, in another point of view as the spirit of man, which he quite distinguishes from the mind:
I pray with the tongue, my spirit prays, but my mind is unfruitful.1 Corinthians 14:14 We are not now, however, speaking of that spirit which is distinct from the mind; and this involves a question relating to itself which is really a difficult one. For in many ways and in various senses the Holy Scriptures make mention of the spirit; but with respect to that we are now speaking of, by which we exercise reason, intelligence, and wisdom, we are both agreed that it is called (and indeed rightly called)
spirit,in such a sense as not to include the entire soul, but a part of it.
Origen, Commentary on Matthew 13.2 (he takes spirit as something of man and of God; also distinguishes from soul; read on in the link):
For, observe, he did not say in the
soulof Elijah, in which case the doctrine of transmigration might have some ground, but
in the spirit and power of Elijah.For the Scripture well knows the distinction between spirit and soul, as,
May God sanctify you wholly, and may your spirit and soul and body be preserved entire, without blame at the coming of our Lord Jesus Christ;1 Thessalonians 5:23 and the passage,
Bless the Lord, you spirits and souls of the righteousas it stands in the book of Daniel, according to the Septuagint, represents the difference between spirit and soul. Elijah, therefore, was not called John because of the soul, but because of the spirit and the power, which in no way conflicts with the teaching of the church, though they were formerly in Elijah, and afterwards in John; and
the spirits of the prophets are subject to the prophets,1 Corinthians 14:32 but the souls of the prophets are not subject to the prophets, and
the spirit of Elijah rested on Elisha.2 Kings 2:15 But we ought to inquire whether the spirit of Elijah is the same as the spirit of God in Elijah, or whether they are different from each other, and whether the spirit of Elijah which was in him was something supernatural, different from the spirit of each man which is in him; for the Apostle clearly indicates that the Spirit of God, though it be in us, is different from the spirit of each man which is in Him, when he says somewhere,
The Spirit itself bears witness with our spirit that we are the children of God;Romans 8:16 and elsewhere,
No one of men knows the things of a man save the spirit of the man which is in him; even so the things of God none knows save the Spirit of God.1 Corinthians 2:11