How To Pray Without Delusion
By Elder John (Alexeev) of Valaam
It is very sad to hear that the priests teach their spiritual children to imagine the Savior, or the Mother of God, or some Saint in the mind while praying.
This method of prayer is wrong, even harmful. I know that the ones who prayed so, became of unsound mind and went to the doctors to be treated.
Taken from: http://www.johnsanidopoulos.com/2012/10/how-to-pray-without-delusion.html?m=0