Surely he is antichrist who denies that Christ has come in the flesh. By declaring that His flesh is simply and absolutely true, and taken in the plain sense of its own nature, the Scripture aims a blow at all who make distinctions in it. In the same way, also, when it defines the very Christ to be but one, it shakes the fancies of those who exhibit a multiform Christ, who make Christ to be one being and Jesus another…
Tertullian
On the Flesh of Christ
Chapter XXIV