The soul, or nous, is a faculty which possesses knowledge

In like manner the mind also, or animus, which the Greeks designate ΝΟΥΣ, is taken by us in no other sense than as indicating that faculty or apparatus which is inherent and implanted in the soul, and naturally proper to it, whereby it acts, whereby it acquires knowledge, and by the possession of which it is capable of a spontaneity of motion within itself, and of thus appearing to be impelled by the mind, as if it were another substance, as is maintained by those who determine the soul to be the moving principle of the universe—the god of Socrates, Valentinus’ “only-begotten” of his father Bythus, and his mother Sige.

…We, however, affirm that the mind coalesces with the soul,—not indeed as being distinct from it in substance, but as being its natural function and agent.

Tertullian
A Treatise on the Soul
Chapter XII

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

Christians do not believe in a preexistent or eternal soul

After settling the origin of the soul, its condition or state comes up next.  For when we acknowledge that the soul originates in the breath of God, it follows that we attribute a beginning to it.  This Plato, indeed, refuses to assign to it, for he will have the soul to be unborn and unmade. We, however, from the very fact of its having had a beginning, as well as from the nature thereof, teach that it had both birth and creation.

Tertullian
A Treatise on the Soul
Chapter IV

Tertullian claims that belief in the soul must have come from the Jewish scriptures first

But, clearly, since the Scriptures of God, whether belonging to Christians or to Jews, into whose olive tree we have been grafted—are much more ancient than any secular literature, (or, let us only say, are of a somewhat earlier date, as we have shown in its proper place when proving their trustworthiness); if the soul have taken these utterances from writings at all, we must believe it has taken them from ours, and not from yours, its instruction coming more naturally from the earlier than the later works.

Tertullian
The Soul’s Testimony
Chapter V

People continue to exist as disembodied souls after death and before the resurrection

Even now, as the matter refers to thy opinion on a point the more closely belonging to thee, in so far as it bears on thy personal well-being, we maintain that after life has passed away thou still remainest in existence, and lookest forward to a day of judgment, and according to thy deserts art assigned to misery or bliss, in either way of it for ever; that, to be capable of this, thy former substance must needs return to thee, the matter and the memory of the very same human being: for neither good nor evil couldst thou feel if thou wert not endowed again with that sensitive bodily organization, and there would be no grounds for judgment without the presentation of the very person to whom the sufferings of judgment were due. That

Tertullian
The Soul’s Testimony
Chapter IV

Mary descended from David

And that the virgin of whom it behoved Christ to be born (as we have above mentioned) must derive her lineage of the seed of David, the prophet in subsequent passages evidently asserts. “And there shall be born,” he says, “a rod from the root of Jesse”—which rod is Mary—“and a flower shall ascend from his root: and there shall rest upon him the Spirit of God, the spirit of wisdom and understanding, the spirit of discernment and piety, the spirit of counsel and truth; the spirit of God’s fear shall fill Him.”

Tertullian
Against the Jews
Chapter IX

Christ is the seal of all prophecy and vision — nothing new is to come

And (then) “righteousness eternal” was manifested, and “an Holy One of holy ones was anointed”—that is, Christ—and “sealed was vision and prophet,” and “sins” were remitted, which, through faith in the name of Christ, are washed away for all who believe on Him. But what does he mean by saying that “vision and prophecy are sealed?” That all prophets ever announced of Him that He was to come and had to suffer. Therefore, since the prophecy was fulfilled through His advent, for that reason he said that “vision and prophecy were sealed;” inasmuch as He is the signet of all prophets, fulfilling all things which in days bygone they had announced of Him. For after the advent of Christ and His passion there is no longer “vision or prophet” to announce Him as to come. In short, if this is not so, let the Jews exhibit, subsequently to Christ, any volumes of prophets, visible miracles wrought by any angels, (such as those) which in bygone days the patriarchs saw until the advent of Christ, who is now come; since which event “sealed is vision and prophecy,” that is, confirmed.  And justly does the evangelist write, “The law and the prophets (were) until John” the Baptist. For, on Christ’s being baptized, that is, on His sanctifying the waters in His own baptism, all the plenitude of bygone spiritual grace-gifts ceased in Christ, sealing as He did all vision and prophecies, which by His advent He fulfilled. Whence most firmly does he assert that His advent “seals visions and prophecy.”

Tertullian
Against the Jews
Chapter VIII

Christ’s name is everywhere worshipped as God and Lord

But Christ’s Name is extending everywhere, believed everywhere, worshipped by all the above-enumerated nations, reigning everywhere, adored everywhere, conferred equally everywhere upon all. No king, with Him, finds greater favour, no barbarian lesser joy; no dignities or pedigrees enjoy distinctions of merit; to all He is equal, to all King, to all Judge, to all “God and Lord.” Nor would you hesitate to believe what we asseverate, since you see it taking place.

Tertullian
Against the Jews
Chapter VII

Tertullian argues that no one is worthy of heaven on the basis of merit

And yet the latter opinion ought to be discussed, that God conferred divine honours in consideration of meritorious claims. Well, then, if the award was made on such grounds, if heaven was opened to men of the primitive age because of their deserts, we must reflect that after that time no one was worthy of such honour; except it be, that there is now no longer such a place for any one to attain to.

Tertullian
Ad Nationes, Book II
Chapter XIII