How does "believe that you have received it" practice in the ​Christian life? in Mark 11:24


  24 Therefore I tell you, whatever
  you ask for in prayer, believe that you have received it, and it will
  be yours.


What is the catholic interpretation of the verse? The reason I'm asking because I wonder if this is the same or similar interpretation as the New Age movements offers?


  You’ve probably heard how visualization is a key part of Law of
  Attraction success. 
  
  “You have to visualize your desire to attract your desire.”


Do we need to go around and visualize or even act like we have already received whatever we asked for in a prayer? How does "believe that you have received it" manifests/practice in the Christian life?  How does it differ from the New Age understanding?
St. Thomas, in his Catena Aurea (Golden Chain) on St. Mark's Gospel, cap. 11 l. 4, cites St. Theophlyact, who writes:


  For whosoever sincerely believes evidently lifts up his heart to God, and is joined to Him, and his burning heart feels sure that he has received what he asked for, which he who has experienced will understand; and those persons appear to me to experience this, who attend to the measure and the manner of their prayers. For this reason the Lord says, "Ye shall receive whatsoever ye ask in faith;" for he who believes that he is altogether in the hands of God, and interceding with tears, feels that he as it were has hold of the feet of the Lord in prayer, he shall receive what he has rightly asked for. Again, would you in another way receive what you ask for? Forgive your brother, if he has in any way sinned against you; this is also what is added: "And when ye stand praying, forgive, if ye have ought against any: that your Father also which is in heaven may forgive you your trespasses."