As muslims, we believe that the Quran is the eternal miracle of Allah and hence, it is the ultimate proof of the truth. However, a christian may make a similar claim about their holy spirit miracles, like healing the blind, speaking in many tongues, etc. Likewise, a christian might even say "Maybe our gospels are also miracles. We just don't know it yet."
So how can I prove it to myself that these so-called "christian miracles" are false or invalid?