Atheism and Miracles
In regards to atheism and miracles, modern scholars are divided on the issue of whether or not David Hume was an atheist. With that caveat in mind, Hume is well known for arguing that it is always more probable that the testimony of a miracle is false than that the miracle occurred. Christian apologists William Lane Craig, Norman Geisler, C.S. Lewis, JP Holding, and others have shown the inadequacy and unreasonableness of Hume's position regarding miracles.   
Impossibly high standards are often set for miracles to be accepted including requirements such as multiple doctor's testimonies from before and after a medical miracle may have occurred along with x-rays and other confidential medical information being made public. These standards, while the default requirement to medically prove a condition and its treatment irregardless if the cause is medicine or a miracle, are impossibly high for an act of God and require faith to believe them. When such evidence is produced it is simply stated to be inadequate or fraudulent.