We know that the Communion of Saints goes from the soul to God or Jesus, from the souls to other souls still struggling in this world, from the soul to Heaven, and from the soul to Purgatory.
There are few ideas upon which St. Margaret Mary insisted as much as the necessity of rendering worthy homage to the Divinity. This is done by offering Jesus to God, by replacing our miserable love with the love of Jesus; this is done by making honorable amends, by assisting at or celebrating Holy Mass with this intention, by fervent and frequent sacramental Communions, by many spiritual communions in which we cry out our thanks to God, by visits to the Eucharist.
Can generous souls thus be souls of reparation and mediation? The Sacred Heart, the saint tells us, desires there to be many of these mediatory souls: “Their office will be to use His credit with God and also to offer to this amiable Heart everything good they do in His honor and for His purposes.”
If talk of mediatory souls were to frighten us, it would mean that we understand nothing about Christianity: just as the sun, a mediator of light between God and us, does no wrong to the divine light but rather glorifies it, so the mediation of our souls that draws all its power from the necessary and universal mediation of Jesus, far from wronging or offending Him, proclaims and honors Him.
Charles Sauvé, Jésus intime.