Men’s souls return to their bodies to be judged

Accordingly, God’s judgment will be more full and complete, because it will be pronounced at the very last, in an eternal irrevocable sentence, both of punishment and of consolation, (on men whose) souls are not to transmigrate into beasts, but are to return into their own proper bodies. And all this once for all, and on “that day, too, of which the Father only knoweth;” (only knoweth,) in order that by her trembling expectation faith may make full trial of her anxious sincerity, keeping her gaze ever fixed on that day, in her perpetual ignorance of it, daily fearing that for which she yet daily hopes.

Tertullian
A Treatise on the Soul
Chapter XXXIII

The soul awaits the last judgement after death. Christ preached to the souls in Hades.

But what is that which is removed to Hades after the separation of the body; which is there detained; which is reserved until the day of judgment; to which Christ also, on dying, descended? I imagine it is the souls of the patriarchs.

Tertullian
A Treatise on the Soul
Chapter VII

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

Christianity is about the death of death

Christianity is a belief, first of all and above all, in the fact that Christ did not remain in the grave, that life shone forth from death, and that in Christ’s Resurrection from the dead, the absolute, all-encompassing law of dying and death, which tolerated no exceptions, was somehow blown apart and overcome from within.

Fr. Alexander Schmemann
The Christian Concept of Death

Christ, the God-man, descended to the dead

Now although Christ is God, yet, being also man, “He died according to the Scriptures,” and “according to the same Scriptures was buried.” With the same law of His being He fully complied, by remaining in Hades in the form and condition of a dead man; nor did He ascend into the heights of heaven before descending into the lower parts of the earth, that He might there make the patriarchs and prophets partakers of Himself. (This being the case), you must suppose Hades to be a subterranean region, and keep at arm’s length those who are too proud to believe that the souls of the faithful deserve a place in the lower regions. These persons, who are “servants above their Lord, and disciples above their Master,” would no doubt spurn to receive the comfort of the resurrection, if they must expect it in Abraham’s bosom. But it was for this purpose, say they, that Christ descended into hell, that we might not ourselves have to descend thither. Well,

Tertullian
A Treatise on the Soul
Chapter LV

The soul is cleansed from sin upon release from the body

In Platonic phrase, indeed, the body is a prison, but in the apostle’s it is “the temple of God,” because it is in Christ. Still, (as must be admitted,) by reason of its enclosure it obstructs and obscures the soul, and sullies it by the concretion of the flesh; whence it happens that the light which illumines objects comes in upon the soul in a more confused manner, as if through a window of horn. Undoubtedly, when the soul, by the power of death, is released from its concretion with the flesh, it is by the very release cleansed and purified: it is, moreover, certain that it escapes from the veil of the flesh into open space, to its clear, and pure, and intrinsic light; and then finds itself enjoying its enfranchisement from matter, and by virtue of its liberty it recovers its divinity, as one who awakes out of sleep passes from images to verities. Then it tells out what it sees; then it exults or it fears, according as it finds what lodging is prepared for it, as soon as it sees the very angel’s face, that arraigner of souls, the Mercury of the poets.

Tertullian
A Treatise on the Soul
Chapter LIII