Christ is the one who said “Let there be light”

Now who was it that said; “Let there be light?” And who was it that said to Christ concerning giving light to the world: “I have set Thee as a light to the Gentiles”—to them, that is, “who sit in darkness and in the shadow of death?” (None else, surely, than He), to whom the Spirit in the Psalm answers, in His foresight of the future, saying, “The light of Thy countenance, O Lord, hath been displayed upon us.” Now the countenance (or person) of the Lord here is Christ. Wherefore the apostle said above: “Christ, who is the image of God.” Since Christ, then, is the person of the Creator, who said, “Let there be light,” it follows that Christ and the apostles, and the gospel, and the veil, and Moses—nay, the whole of the dispensations—belong to the God who is the Creator of this world, according to the testimony of the clause (above adverted to), and certainly not to him who never said, “Let there be light.”

Tertullian
The Five Books Against Marcion, Book V
Chapter XI

Marcion preached only a resurrection of the soul

For Marcion does not in any wise admit the resurrection of the flesh, and it is only the salvation of the soul which he promises; consequently the question which he raises is not concerning the sort of body, but the very substance thereof. Notwithstanding, he is most plainly refuted even from what the apostle advances respecting the quality of the body, in answer to those who ask, “How are the dead raised up? with what body do they come?” For as he treated of the sort of body, he of course ipso facto proclaimed in the argument that it was a body which would rise again.

Tertullian
The Five Books Against Marcion, Book V
Chapter X

Christ is the High Priest of both the circumcision and the uncircumcision

Christ is the proper and legitimate High Priest of God. He is the Pontiff of the priesthood of the uncircumcision, constituted such, even then, for the Gentiles, by whom He was to be more fully received, although at His last coming He will favour with His acceptance and blessing the circumcision also, even the race of Abraham, which by and by is to acknowledge Him.

Tertullian
The Five Books Against Marcion, Book V
Chapter IX

Only a body dies so therefore resurrection is of the body, not the soul

Now the body is that which loses life, and as the result of losing it becomes dead. To the body, therefore, the term dead is only suitable. Moreover, as resurrection accrues to what is dead, and dead is a term applicable only to a body, therefore the body alone has a resurrection incidental to it. So again the word Resurrection, or (rising again), embraces only that which has fallen down. “To rise,” indeed, can be predicated of that which has never fallen down, but had already been always lying down. But “to rise again” is predicable only of that which has fallen down; because it is by rising again, in consequence of its having fallen down, that it is said to have re-risen.

Tertullian
The Five Books Against Marcion, Book V
Chapter IX

The sacrament as Christ’s body and blood is denied by the heretics

In like manner, when treating of the gospel, we have proved from the sacrament of the bread and the cup the verity of the Lord’s body and blood in opposition to Marcion’s phantom;

Tertullian
The Five Books Against Marcion, Book V
Chapter VIII

The incarnation of God is the weakness of God though stronger than men

Now, what is that “foolishness of God which is wiser than men,” but the cross and death of Christ? What is that “weakness of God which is stronger than men,” but the nativity and incarnation of God?

Tertullian
The Five Books Against Marcion, Book V
Chapter V

Christ, as God, descended to Hades so that we won’t have to

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.

Tertullian
A Treatise on the Soul
Chapter LV

The soul is cleansed and purified upon death

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