But, He mastered the flesh. It enabled Him to put His flesh under the submission of the spirit and pray that God's will would be accomplished in His human flesh. Just like the Lord's Prayer, it was not a qialifier, but an individual submission of human will to God's will. Yes, to a great extent it does. But, let us look at the passage in I John a little more closely, and we'll see that there is no contadiction with Jesus' words in Mark 11.
Confidence means certainty or trustworthiness.
This is something we can be certain of and have trust in. He hears us. It just says that God hears us. Actually, of course, God hears everything we say. This seems certainly to be in line with Jesus' words in Mark 11.