I like what B.B. Warfield said in his book, [u]Counterfeit Miracles [/u]
...But we see no indication in the passage that "a peculiar miraculous faith" is intended; no promise of a healing in a specifically miraculous manner; and no command to exclude medicinal means, or proof of their exclusion. If we read the passage with simple minds, free from preconceptions, I think we shall find in it nothing but a very earnest exhortation to sick people to turn to the Lord in their extremity, and a very precious promise to those who thus call upon Him, that the Lord will surely hearken to their cry."