1. Jesus rebukes his disciples for not being able to heal the man, he tells them three things needed to heal, those were faith, prayer, and fasting.
2. 3 Nephi 18:20 - in this reference it talks about how prayer is needed for miracles to happen, we need to ask the Father and then believe that it will be given unto us.
D&C 50:29 - we have to be purified from sin before we ask for a miracle to happen.
D&C 42:48 - the last one is we have to have faith.