The Cloud of Unknowing

"Our intense need to understand will always be a powerful stumbling block to our attempts to reach God in simple love [...] and must always be overcome. For if you do not overcome this need to understand, it will undermine your quest. It will replace the darkness which you have pierced to reach God with clear images of something which, however good, however beautiful, however Godlike, is not God."

"And so I urge you, go after experience rather than knowledge. On account of pride, knowledge may often deceive you, but this gentle, loving affection will not deceive you. Knowledge tends to breed conceit, but love builds. Knowledge is full of labor, but love, full of rest."

http://en.wikipedia.org/wiki/The_Cloud_of_Unknowing