The Enchiridion

The bodies of the saints, then, shall rise again free from every defect, from every blemish, as from all corruption, weight, and impediment. For their ease of movement shall be as complete as their happiness. Whence their bodies have been called spiritual, though undoubtedly they shall be bodies and not spirits. For just as now the body is called animate, though it is a body, and not a soul [anima], so then the body shall be called spiritual, though it shall be a body, not a spirit. Hence, as far as regards the corruption which now weighs down the soul, and the vices which urge the flesh to lust against the spirit, it shall not then be flesh, but body; for there are bodies which are called celestial.

Wherefore it is said, “Flesh and blood cannot inherit the kingdom of God;” and, as if in explanation of this, “neither does corruption inherit incorruption.” What the apostle first called “flesh and blood,” he afterwards calls “corruption;” and what he first called “the kingdom of God,” he afterwards calls “incorruption.” But as far as regards the substance, even then it shall be flesh. For even after the resurrection the body of Christ was called flesh. The apostle, however, says: “It is sown a natural body; it is raised a spiritual body;” because so perfect shall then be the harmony between flesh and spirit, the spirit keeping alive the subjugated flesh without the need of any nourishment, that no part of our nature shall be in discord with another; but as we shall be free from enemies without, so we shall not have ourselves for enemies within.