And further assumes that,

1)  People are aware of their sickness/illness/need for healing;

and

2)  if so aware, are capable of self-healing.

I have great respect for +Ambrose, in no small part for being the one who Bapized +Augustine of Hippo; but this quotation is not one of his finer sayings.

This one, on the other hand:

So that no one might escape the bath of grace, He, Christ, did not flee
    from the bath of repentance.  So that no one may be called free from sins,
    He, Christ came to cure sins.  If, for us, Christ was washed--moreover,
    if He washed us in His body---how much more must we wash ourselves
    from our own faults....

    Alone He was immersed into the water, but He raised up all!   Alone He
    descended, but in order that we all might rise again!  Alone He took upon
    Himself the sin of all, but in order that in Him the sin of all might be cleansed!