Some works were known but not included as “ecclesiastical books”

The term ἀσώματον, i.e., incorporeal, is disused and unknown, not only in many other writings, but also in our own Scriptures.  And if any one should quote it to us out of the little treatise entitled The Doctrine of Peter, in which the Saviour seems to say to His disciples, “I am not an incorporeal demon,” I have to reply, in the first place, that that work is not included among ecclesiastical books; for we can show that it was not composed either by Peter or by any other person inspired by the Spirit of God.

Origen
On First Principles, Book I
Preface

The Scriptures are not clear to all

Then, finally, that the Scriptures were written by the Spirit of God, and have a meaning, not such only as is apparent at first sight, but also another, which escapes the notice of most.  For those (words) which are written are the forms of certain mysteries, and the images of divine things.  Respecting which there is one opinion throughout the whole Church, that the whole law is indeed spiritual; but that the spiritual meaning which the law conveys is not known to all, but to those only on whom the grace of the Holy Spirit is bestowed in the word of wisdom and knowledge.

Origen
On First Principles, Book I
Preface

The Church’s understanding of creation and the end

This also is a part of the Church’s teaching, that the world was made and took its beginning at a certain time, and is to be destroyed on account of its wickedness.  But what existed before this world, or what will exist after it, has not become certainly known to the many, for there is no clear statement regarding it in the teaching of the Church.

Origen
On First Principles, Book I
Preface

The devil is a fallen angel

Regarding the devil and his angels, and the opposing influences, the teaching of the Church has laid down that these beings exist indeed; but what they are, or how they exist, it has not explained with sufficient clearness.  This opinion, however, is held by most, that the devil was an angel, and that, having become an apostate, he induced as many of the angels as possible to fall away with himself, and these up to the present time are called his angels.

Origen
On First Principles, Book I
Preface

Origen is not sure on the origin of the soul

But with respect to the soul, whether it is derived from the seed by a process of traducianism, so that the reason or substance of it may be considered as placed in the seminal particles of the body themselves, or whether it has any other beginning; and this beginning, itself, whether it be by birth or not, or whether bestowed upon the body from without or no, is not distinguished with sufficient clearness in the teaching of the Church.

Origen
On First Principles, Book I
Preface

The soul is judged according to its works

After these points, also, the apostolic teaching is that the soul, having a substance and life of its own, shall, after its departure from the world, be rewarded according to its deserts, being destined to obtain either an inheritance of eternal life and blessedness, if its actions shall have procured this for it, or to be delivered up to eternal fire and punishments, if the guilt of its crimes shall have brought it down to this:  and also, that there is to be a time of resurrection from the dead, when this body, which now “is sown in corruption, shall rise in incorruption,” and that which “is sown in dishonour will rise in glory.”  This also is clearly defined in the teaching of the Church, that every rational soul is possessed of free-will and volition; that it has a struggle to maintain with the devil and his angels, and opposing influences, because they strive to burden it with sins; but if we live rightly and wisely, we should endeavour to shake ourselves free of a burden of that kind.

Origen
On First Principles, Book I
Preface

The Son and the Spirit are also God

Jesus Christ Himself, who came (into the world), was born of the Father before all creatures; that, after He had been the servant of the Father in the creation of all things—“For by Him were all things made”—He in the last times, divesting Himself (of His glory), became a man, and was incarnate although God, and while made a man remained the God which He was; that He assumed a body like to our own, differing in this respect only, that it was born of a virgin and of the Holy Spirit:  that this Jesus Christ was truly born, and did truly suffer, and did not endure this death common (to man) in appearance only, but did truly die; that He did truly rise from the dead; and that after His resurrection He conversed with His disciples, and was taken up (into heaven).

Then, Thirdly, the apostles related that the Holy Spirit was associated in honour and dignity with the Father and the Son.  But in His case it is not clearly distinguished whether He is to be regarded as born or innate, or also as a Son of God or not:  for these are points which have to be inquired into out of sacred Scripture according to the best of our ability, and which demand careful investigation.  And that this Spirit inspired each one of the saints, whether prophets or apostles; and that there was not one Spirit in the men of the old dispensation, and another in those who were inspired at the advent of Christ, is most clearly taught throughout the Churches.

Origen
On First Principles, Book I
Preface

Apostolic tradition “alone” is the source of authority

…as the teaching of the Church, transmitted in orderly succession from the Apostles, and remaining in the Churches to the present day, is still preserved, that alone is to be accepted as truth which differs in no respect from ecclesiastical and apostolical tradition.

Origen
On First Principles, Book I
Preface

Grace and truth were obtained through Christ

All who believe and are assured that grace and truth were obtained through Jesus Christ, and who know Christ to be the truth, agreeably to His own declaration, “I am the truth,” derive the knowledge which incites men to a good and happy life from no other source than from the very words and teaching of Christ.

Origen
On First Principles, Book I
Preface

The departed saints pray for us by being joined together with us by God

Now one of these excellences in the strictest sense according to the divine word is love for one’s neighbor, and this accordingly we are compelled to think of as possessed in a far higher degree by saints already at rest than by those who are in human weakness and wrestle on along with the weaker. It is not only here that “if one member suffers, all the members suffer with it and if one member is glorified, all the members rejoice with it” in the experience of those who love their brethren, for it beseems the love also of those who are beyond the present life to say “I have anxiety for all the churches:

Who is weak and I am not weak? Who is made to stumble and I do not burn?” Especially when Christ avows that according as such one of the saints may be weak, He is weak in like manner, and in prison and naked and a stranger and hungry and athirst. For who that reads the gospel is ignorant that Christ, in taking on himself whatever befalls believers, counts their sufferings His own?

And if angels of God came to Jesus and ministered to Him, and if we are not to think of the ministry of the angels to Jesus as having been limited to the brief space of His bodily sojourn among men while He was still in the midst of believers not as one that reclined at table but as one that ministered, how many angels, I wonder, must now be ministering to Jesus when He would “bring together the Children of Israel one by one” and gather them from the dispersion, saving those who fear God and call upon Him, and must be cooperating more than the apostles in the increase and enlargement of the church! Thus in John certain angels are spoken of in the Apocalypse as actually presiding over the churches.

Not in vain do angels of God ascend and descend unto the Son of Man, beheld of eyes that have been enlightened with the light of knowledge. In the very season of prayer, accordingly, being reminded by the suppliant of his needs, they satisfy them as they have ability by virtue of their general commission. To further the acceptance of our view we may make use of some such image as the following in support of this argument.

Suppose that a righteously minded physician is at the side of a sick man praying for health, with knowledge of the right mode of treatment for the disease about which the man is offering prayer. It is manifest that he will be moved to heal the suppliant, surmising, it may well be not idly, that God has had this very action in mind in answer to the prayer of the suppliant for release from the disease. Or suppose that a man of considerable means, who is generous, hears the prayer of a poor man offering intercession to God for his wants. It is plain that he, too, will fulfil the objects of the poor man’s prayer, becoming a minister of the fatherly counsel of Him who at the season of the prayer had brought together him who was to pray and him who was able to supply and by virtue of the rightness of his principles, incapable of overlooking one who has made that particular request.

As therefore we are not to believe that these events are fortuitous, when they take place because He who has numbered all the hairs of the head of saints, has aptly brought together at the season of the prayer the hearer who is to be minister of His benefaction to the suppliant and the man who has made his request in faith; so we may surmise that the presence of the angels who exercise oversight and ministry for God is sometimes brought into conjunction with a particular suppliant in order that they may join in breathing his petitions.

Nay more, beholding ever the face of the Father in heaven and looking on the Godhead of our Creator, the angel of each man, even of “little ones” within the church, both prays with us, and acts with us where possible, for the objects of our prayer.

Origen
On Prayer
Chapter VI