For verily I say unto you, That whosoever shall say unto this mountain, Be removed, and be cast into the sea; and shall not doubt in his heart, but shall believe that those things which he said shall come to pass; he shall have whatsoever he said.
All Commentaries on Mark 11:23 Go To Mark 11
John Cassian
AD 435
While we are praying, there should be no hesitation that would intervene or break down the confidence of our petition by any shadow of despair. We know that by pouring forth our prayer we are obtaining already what we are asking for. We have no doubt that our prayers have effectually reached God. For to that degree that one believes that he is regarded by God, and that God can grant it, just so far will one be heard and obtain an answer. .