They (speaking of miracles) are only a part of the total picture of Jesus' ministry, only one aspect of the unique authority which Jesus displayed. Indeed they are far from being at the centre of Jesus' mission; he was very much more than just a miracle worker. Faith based on his miracles alone would be too shallow: this is a regular theme of the Fourth Gospel, and it may well be the reason for his reticence in allowing the report of his miracles to spread too widely. He had more to accomplish than merely to go down in history as a nine-days' wonder.
France, R. T. A Portrait of Jesus. Inter-Varsity Press. London. 1975. p.78-79.