For a very long time the mystery of the Trinity seemed to be most commonly presented in terms first of its essential unity and second, of the work of the three divine persons which comprise that unity; the Father, the Son, and the Holy Spirit. Now there is so much more being said about the relationship between and among these persons. Because we are created in the image and likeness of God, destined from all time to be one with God through the further mystery of the Incarnation ("God became man that man might become God." St. Athanatius), the characteristics of relationship within the Trinity are to me emulated by us. This is a model of perfect oneness and mutuality, giving and receiving, no distinctions although there is difference.
Recently I picked up a work by Aelred of Rievaulx, a 12th century Cistercian monk, Treatises - Pastoral Prayer. It is pretty heavy going but I was moved by his words regarding how the monastic who takes a vow of poverty must fulfill the universal call to charity. What are they to do since they have nothing to give away? I hope you do not find it too much of a stretch to see how his answer to that question is an illustration of how praying people are called to emulate Trinitarian life in relationship.
What good then will you be able to do to your neighbor? Nothing is more valuable, a certain holy man has said, that good will. Let this be your offering. What is more useful that prayer. Let this be your largesse. What is more humane than pity? Let this be your alms. So embrace the whole world with the arms of your love and in that act at once consider and congratulate the good, contemplate and mourn over the wicked. In that act look upon the afflicted and the oppressed and feel compassion for them. In that act call to mind the wretchedness of the poor, the groans of orphans, the abandonment of widows, the gloom of the sorrowful, the needs of travelers, the prayers of virgins, the perils of those at sea, the temptations of monks, the responsibilities of prelates, the labors of those waging war. In your love take them to your heart, weep over them, offer your prayers for them. Such alms are more pleasing to God, more acceptable to Christ, more becoming to your profession, more fruitful to those who receive them. The performance of such good works as these help you to live out your profession instead of upsetting you; they increase the love you have for your neighbor instead of diminishing it; they are a safeguard, not an obstacle to tranquillity of mind.
The Rule of Life for a Recluse, Part 2, #28