However, it is true that Jesus' miracles indirectly speak of his deity. They do so inasmuch as Jesus' miracles prove his special anointing by the Spirit which in turn support his claims to be 'from God'. As Bruce Ware comments:
...in response to the challenge to declare whether he was in fact the Christ, Jesus said in John 10:25 “I told you, and you do not believe; the works that I do in My Father’s name, these testify of Me.” So, the “works” of Jesus testify to the truthfulness of his “words.” When he declares with words, “Before Abraham was, I am” (John 8:58), and “I and the Father are one” (John 10:30), these “words” that declare his deity are confirmed and authenticated by the “works” (i.e., miracles) that he does. That is, he is the Messiah of God, he is the God-man, and one way we know this is that he does works only God can do when he performs these works in the power of the Spirit. (Interview with Bruce Ware, http://mydigitalseminary.wordpress.com/2012/11/24/an-interview-with-bruce-ware/)Now, R.C. Sproul has posted a helpful article entitled 'Does R.C. Sproul Believe in Miracles?'. The short answer is 'no' but he goes on to give some good justification as to why not. Interestingly, he roots his rejection of modern day miracles (according to his own tight definition) in the same premise as the above. Namely, he doesn't expect to see miracles today because miracles act as a proof of God's special anointing for a specific task. Given that he doesn't expect to see Apostles (or, presumably, Messiahs) around today, he equally doesn't expect to see miracles either.
It's an interesting article worth a read.