Daughter, your heart feels hardened and unable to pray? Do not be distressed. God can make even the stones to speak. Let yourself rest in Him even though your soul is restless. For in your very depths the most sweet and divine operation takes place. God nourishes Himself on your spirit and your spirit sustains itself on the Spirit of God. This mutual indwelling and embrace of love does not depend on your feelings.
Prayer is never more perfect than when it ascends from the very depth and essence of the soul ; we pray, then, in the spirit of God. This is a sublime language, but when God wills, He makes even the stones speak. Let the sovereign God reign in your spirit ; there ought to be a reciprocal repose : God in you, and you in God. O sweet, O divine operation ! God nourishes Himself, let me say for want of a better word — God nourishes Himself with your spirit, and your spirit sustains herself with the Spirit of God : Jesus is my nourishment, and I am His. There is no illusion possible in this operation, because it is a labor of faith and love.
St. Paul of the Cross