Some people ask for signs to reveal them that God is Real. They ask for very big miracles, just like the above one. And even if somehow it happens, they will find another way out not to believe it.
But, one may not wait for these great signs to reveal to him on God’s existence. The simple fact that one is alive today is a sign. God works daily in our lives, executing His plan about us. Try to spot Him working through our lives through simple incidents. And for an Atheist, even the miracle above will not be enough to become a theist.