Article 19: The Two Natures of Christ
We believe that by being thus conceived the person of the Son has been inseparably united and joined together with human nature, in such a way that there are not two Sons of God, nor two persons, but two natures united in a single person, with each nature retaining its own distinct properties.
Thus his divine nature has always remained uncreated, without beginning of days or end of life,
filling heaven and earth. Christ’s human nature has not lost its properties but continues to have those of a creature—it has a beginning of days; it is of a finite nature and retains all that belongs to a real body. And even though he, by his resurrection, gave it immortality, that nonetheless did not change the reality of his human nature; for our salvation and resurrection depend also on the reality of his body.
But these two natures are so united together in one person that they are not even separated by his death.
So then, what he committed to his Father when he died was a real human spirit which left his body. But meanwhile his divine nature remained united with his human nature even when he was lying in the grave; and his deity never ceased to be in him, just as it was in him when he was a little child, though for a while it did not show itself.
These are the reasons why we confess him to be true God and truly human—true God in order to conquer death by his power, and truly human that he might die for us in the weakness of his flesh.