The Elder Porphyrios, in Wounded by Love:
When simplicity is lacking and you say, 'I'll do this, that and the other, and God will give me what I ask for', then nothing happens. Yes indeed, I should do this, that and the other, but with such secrecy and such simplicity and such meekness, that even I who ask for the thing am unconscious of it.See also "Simplicity" - Chapter 87 from Father Seraphim Rose: His Life and Works.
Do everything simply and meekly. Do nothing with ulterior motives. Don't say 'I'll do this in order to have that result', but do it naturally, without taking cognizance of it. That is, pray simply and don't think about what God will bestow on your soul. Don't make any calculations. You know of course, what God bestows when you enter into communion with Him, but it is as if you don't know. ...
Your heart must be simple, and not divided and dishonest, sincere and not devious and self-seeking. All people desire to find a good and simple soul; they feel comfortable with such a person and they approach him without fear and without suspicion. And such a person lives with inner peace ad has good relations with everyone and with all creation.