The early Church held closed communion and the Romans spied on them and spread rumors

But why need I disparagingly refer to strange spies and informers, when you allege against us such charges as we certainly do not ourselves divulge with very much noise—either as soon as you hear of them, if we previously show them to you, or after you have yourselves discovered them, if they are for the time concealed from you? For no doubt, when any desire initiation in the mysteries, their custom is first to go to the master or father of the sacred rites.  Then he will say (to the applicant), You must bring an infant, as a guarantee for our rites, to be sacrificed, as well as some bread to be broken and dipped in his blood; you also want candles, and dogs tied together to upset them, and bits of meat to rouse the dogs.  Moreover, a mother too, or a sister, is necessary for you. What, however, is to be said if you have neither? I suppose in that case you could not be a genuine Christian. Now, do let me ask you, Will such things, when reported by strangers, bear to be spread about (as charges against us)? It is impossible for such persons to understand proceedings in which they take no part. The first step of the process is perpetrated with artifice; our feasts and our marriages are invented and detailed by ignorant persons, who had never before heard about Christian mysteries. And though they afterwards cannot help acquiring some knowledge of them, it is even then as having to be administered by others whom they bring on the scene. Besides, how absurd is it that the profane know mysteries which the priest knows not!  They keep them all to themselves, then, and take them for granted; and so these tragedies, (worse than those) of Thyestes or Œdipus, do not at all come forth to light, nor find their way to the public. Even more voracious bites take nothing away from the credit of such as are initiated, whether servants or masters. If, however, none of these allegations can be proved to be true, how incalculable must be esteemed the grandeur (of that religion) which is manifestly not overbalanced even by the burden of these vast atrocities! O ye heathen; who have and deserve our pity, behold, we set before you the promise which our sacred system offers. It guarantees eternal life to such as follow and observe it; on the other hand, it threatens with the eternal punishment of an unending fire those who are profane and hostile; while to both classes alike is preached a resurrection from the dead.

Tertullian
Ad Nationes, Book I
Chapter VII

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

Origen quotes the Deuterocanon in support of the Intercession of Saints

But these pray along with those who genuinely pray—not only the high priest but also the angels who “rejoice in heaven over one repenting sinner more than over ninety-nine righteous that need not repentance,” and also the souls of the saints already at rest. Two instances make this plain. The first is where Raphael offers their service to God for Tobit and Sarah. After both had prayed, the scripture says, “The prayer of both was heard before the presence of the great Raphael and he was sent to heal them both,” and Raphael himself, when explaining his angelic commission at God’s command to help them, says:

“Even now when you prayed, and Sarah your daughter-in-law, I brought the memorial of your prayer before the Holy One,” and shortly after, “I am Raphael, one of the Seven angels who present the prayers of saints and enter in before the glory of the Holy One. Thus, according to Raphael’s account at least, prayer with fasting and almsgiving and righteousness is a good thing.

The second instance is in the Books of the Maccabees where Jeremiah appears in exceeding “white haired glory” so that a wondrous and most majestic authority was about him, and stretches forth his right hand and delivers to Judas a golden sword, and there witnesses to him another saint already at rest saying, “This is he who prays much for the people and the sacred city, God’s prophet Jeremiah.” For it is absurd when knowledge, though manifested to the worthy through a mirror and in a riddle for the present, is then revealed face to face not to think that the like is true of all other excellences as well, that they who prepare in this life beforehand are made strictly perfect then.

Origen
On Prayer
Chapter VI

The departed saints join in our prayers

Yet there is a certain helpful charm in a place of prayer being the spot in which believers meet together. Also it may well be that the assemblies of believers also are attended by angelic powers, by the powers of our Lord and Savior himself, and indeed by the spirits of saints, including those already fallen asleep, certainly of those still in life, though just how is not easy to say.

And if Paul, while still wearing the body, believed that he assisted in Corinth with his spirit, we need not abandon the belief that the blessed departed in spirit also, perhaps more than one who is in the body, make their way likewise into the churches. For that reason we ought not to despise prayer in churches, recognizing that it possesses a special virtue for him who genuinely joins in.

Origen
On Prayer
Chapter XX

The order of private prayer

In the beginning and opening of prayer, glory is to be ascribed according to one’s ability to God, through Christ who is to be glorified with Him, and in the Holy Spirit who is to be proclaimed with Him.

Thereafter, one should put thanksgivings: common thanksgivings—into which he introduces benefits conferred upon men in general—and thanksgivings for things which he has personally received from God. After thanksgiving it appears to me that one ought to become a powerful accuser of one’s own sins before God and ask first for healing with a view to being released from the habit which brings on sin, and secondly for forgiveness for past actions. After confession it appears to me that one ought to append as a fourth element the asking for the great and heavenly things, both personal and general, on behalf of one’s nearest and dearest. And last of all, one should bring prayer to an end ascribing glory to God through Jesus Christ in the Holy Spirit. As I already said, I have found these points scattered throughout the scriptures.

Origen
On Prayer
Chapter XX

Praying facing East is the ancient Christian tradition

Of the four directions, the North, South, East, and West, who would not at once admit that the East clearly indicates the duty of praying with the face turned towards it with the symbolic suggestion that the soul is looking upon the dawn of the true light?

Should anyone, however, prefer to direct his intercessions according to the aperture of the house, whichever way the doors of the house may face, saying that the sight of heaven appeals to one with a certain attraction greater than the view of the wall, and the eastward part of the house having no opening, we may say to him that since it is by human arrangement that houses are open in this or that direction but by nature that the East is preferred to all the other directions, the natural is to be set before the artificial. Besides, on that view why should one who wished to pray when in the open country pray to the East in preference to the West? If, in the one case it is reasonable to prefer the East, why should the same not be done in every case? Enough on that subject.

Origen
On Prayer
Chapter XX

The Nature of the Logos

The name Word bestowed upon the Son of God reveals better than any other name the mystery of the inner relationship between the First and Second Persons of the Holy Trinity, God the Father and God the Son. A thought and a word are distinct from each other in that the thought dwells in the mind, whereas the word is the expression of the thought; yet the two are inseparable. The thought does not exist without the word, nor does the word without the thought. A thought is like a word which is concealed within, and a word is that which gives expression to the thought. The thought takes the form of a word to convey the content of the thought to its hearers. Looked at in this way, the thought, being an independent principle, is the father of the word, and the word is the son of the thought. The word cannot exist prior to the thought, yet it does not originate from without; it comes from the thought and remains inseparable from the thought. Similarly, the Father, the supreme and all-encompassing Thought, produced from His bosom the Son, the Word, His first Interpreter and Herald.

St. Dionysius of Alexandria
The Logos, 230-265 A.D.

Not everything is found in Holy Scripture

If, for these and other such rules, you insist upon having positive Scripture injunction, you will find none. Tradition will be held forth to you as the originator of them, custom as their strengthener, and faith as their observer. That reason will support tradition, and custom, and faith, you will either yourself perceive, or learn from some one who has.

…This instances, therefore, will make it sufficiently plain that you can vindicate the keeping of even unwritten tradition established by custom; the proper witness for tradition when demonstrated by long-continued observance.

Tertullian
The Chaplet
Chapter IV

The Real Presence was prefigured in the Old Covenant

When He so earnestly expressed His desire to eat the passover, He considered it His own feast; for it would have been unworthy of God to desire to partake of what was not His own. Then, having taken the bread and given it to His disciples, He made it His own body, by saying, “This is my body,” that is, the figure of my body. A figure, however, there could not have been, unless there were first a veritable body. An empty thing, or phantom, is incapable of a figure. If, however, (as Marcion might say,) He pretended the bread was His body, because He lacked the truth of bodily substance, it follows that He must have given bread for us. It would contribute very well to the support of Marcion’s theory of a phantom body, that bread should have been crucified!  But why call His body bread, and not rather (some other edible thing, say) a melon, which Marcion must have had in lieu of a heart!  He did not understand how ancient was this figure of the body of Christ, who said Himself by Jeremiah: “I was like a lamb or an ox that is brought to the slaughter, and I knew not that they devised a device against me, saying, Let us cast the tree upon His bread,” which means, of course, the cross upon His body. And thus, casting light, as He always did, upon the ancient prophecies, He declared plainly enough what He meant by the bread, when He called the bread His own body. He likewise, when mentioning the cup and making the new testament to be sealed “in His blood,” affirms the reality of His body. For no blood can belong to a body which is not a body of flesh.

…Much more clearly still does the book of Genesis foretell this, when (in the blessing of Judah, out of whose tribe Christ was to come according to the flesh) it even then delineated Christ in the person of that patriarch, saying, “He washed His garments in wine, and His clothes in the blood of grapes”—in His garments and clothes the prophecy pointed out his flesh, and His blood in the wine. Thus did He now consecrate His blood in wine, who then (by the patriarch) used the figure of wine to describe His blood.

Tertullian
The Five Books Against Marcion, Book IV
Chapter XL

Christ receives the prayers of the saints

For as much, then, as there is but one Son of man whose advent is placed between the two issues of catastrophe and promise, it must needs follow that to that one Son of man belong both the judgments upon the nations, and the prayers of the saints.

Tertullian
The Five Books Against Marcion, Book IV
Chapter XXXIX