John Chrysostom
What manner of healing is this? What mystery is being indicated to us here?
This was not written idly or without cause. Here the future is set before us in image and likeness, so that, when something very unusual and unexpected should occur, the strength of faith in many would not be shaken.
What then is depicted here? The intention was to grant us baptism, which possesses great power and the greatest blessings. It cleanses from all sins and makes the dead living.
This, as in an image, is prefigured here in the pool, as also in many other ordinances.
Thus God first gave water that cleansed bodily impurities, not impurities in substance, but those only seeming to be such. Such were impurities from touching the dead, from leprosy, and from similar causes.
Read more (375 words)
We see that much in the Old Testament was also performed by means of water for this purpose. But let us return to our subject.
As I said, God first established purification by water for bodily impurities, and afterward for various diseases as well. Wishing to bring us nearer and nearer to the grace of baptism, He now heals not only impurities, but also diseases.
Indeed, images nearer to the truth, that is, nearer in time to the New Testament, were generally clearer than the more ancient types. This is true regarding baptism, the Passion, and other matters.
As the shield-bearers nearest the king shine more brightly than those standing far away from him, so it was also with the foreshadowings.
An angel descended and troubled the water, giving it healing power, in order to teach the Jews that the Lord of angels can all the more heal every disease of the soul.
Here, it was not simply the natural power of water that healed. Otherwise this would have happened always. Rather, it healed through the action of the angel.
So also with us, the water does not act by itself. When it receives the grace of the Spirit, then it cleanses all sins.
Around this pool lay a great multitude of the sick, the blind, the lame, and the withered, waiting for the movement of the water.
Then weakness hindered the one who wished to receive healing. Now everyone may approach freely.
It is not an angel who troubles the water, but the Lord of angels who accomplishes all this. No sick man can now say, “I have no man, and when I am coming, another steps down before me” (Jn 5:7).
Even if the whole world were to gather, grace is not diminished and its power is not exhausted. It remains always the same as before.
As the rays of the sun shine every day and are not exhausted, so even more the power of the Spirit is not diminished at all by the multitude of those who receive it.
This was done so that those who saw bodily diseases healed by water, and experienced this for a long time, might more readily believe that diseases of the soul can also be healed.