The divine Maximos says in one place: "In everything that we do God searches out our purpose to see whether we do it for Him or for some other motive", and in another place that: "The demons do not hate self-restraint, fasting, almsgiving, hospitality, the singing of psalms ... or any of the other things which characterize a life lived according to God, so long as the aim and purpose of a person trying to live such a life are tilted in their direction."
As Quoted in St. Nikodemos' Exomologetarion, pp103-104, Uncut Mountain Press