Some Cayce quotes to get you started:
As thou hast known, and DO know in thine experience as to how desire in the material may be spiritualized by making the desire as "Thy will, Thy purpose, Thy way be done in and through me; as the Father seeth fit, use me," so give expression of same in such a manner that it may be helpful to thy fellow man. "Not my will, not my desire, save that desire be in accord with Thy purpose of the God that manifests itself in and through me as TO my attitude, my purpose, my desire, towards my fellow man." (262-70)
… desire is that impulse which makes for the activity of the mental body … (276-7)
And the mental self is dependent upon the spirit, the purpose, the desire, the hope with which ye entertain ideas, and these lead to the choice of ideals and manner of activity. (3392-1)
Desire, as will, is a portion then of the spiritual self. It is a continuous thing. Then gratifying of self, or the gratification for itself alone, may oft turn and rend they that would indulge in same without standards, ideals, or the showing forth of a purposefulness in the experience or activity. (1597-1)
(Q) Is it probable that we will again be closely associated or separated?
(A) This depends upon the desire. For as creative activities are applied, what ye desire becomes law. (5265-1)
Consider, first, that as was given as to how the outline should be divided, for, the dealings are with that as partakes of the spiritual in its highest sense and of material in its most destructive or degrading sense. For, as is presented, the presentation to an active force of DESIRE is to set in motion those things that become miracles or crimes in the experiences of individuals. (262-71)
For it has been given that the desires of the heart that are of the spiritual forces in application are spiritual desires; while those that are for the comforts, or ease, or gratification of self's own interest, are born of the earth and do bring confusion to those that seek even the clarification in their own minds when meeting, contemplating those things that pertain to the spirit. (262-69)
There are the spiritual attributes, desire, hope, will, - that function through the organs of reproduction, as well as becoming the import or motivative force in expression even in a material manner through the senses of the body; the eye, the ear, the taste, the feeling. (2114-1)
Wishes do not bring other than desire. Is desire of that that builds in the proper sense, in the proper order with spirit, soul or mind AND body? for the spirit is life; the mind is the builder; the physical is the result. Guide, keep, self aright. (349-4)
(Q) The first problem concerns the reason for creation. Should this be given as God's desire to experience Himself,
God's desire for companionship, God's desire for expression, or in some other way?
(A) God's desire for companionship and expression. (5749-14)