Are miracles evidence of the existence of God?

[Simon Moon]

Granted, if one arbitrarily defines a miracle as an act of God...then one might say the existence of a realTM miracle would prove God existed.  But if we just define a miracle as something that is not explainable by natural laws or science, then I don't think it would be evidence of the existence of God.

For argument sake, let's assume something inexplicable actually happened.

First, one would have to know that whatever happened was actually impossible to have been due to natural laws or causes.  It seems there is enough we don't know about the natural world that that is unlikely to ever be known.

Second, even IF one COULD know for certain that whatever happened could not have been due to 'natural laws' and/or nature, that would still leave other plausible explanations..e.g. some 'outside of nature' or 'supernatural' force that either acts randomly/inexplicably or that could be somehow controlled by humans or other beings with minds,  Of course this  explanation would be evidence of some sort of supernatural and maybe even that (some) human minds can access. 

From a personal standpoint, I'm not convinced any actual miracles (events that cannot be explained through nature) have ever occurred, although I have heard some pretty remarkable stories from people I believe were telling what they thought to be true.

First of all, if something inexplicable occurred, then that's what it is, inexplicable. Claiming something inexplicable occurred, then explaining it by claiming it is a miracle, sounds like an argument from ignorance fallacy.

And second, you are correct, even if an event seems like it breaks all natural laws, where is the justification to claim it was caused by a god? How were all other unknown explanations ruled out?

For a god to be considered as an explanation, there has to be some justification to consider it a possible explanation. And possibility has to be demonstrated.