At the beginning of his extended treatise on the Eucharist in the Summa Theologiae, St. Thomas draws a parallel between our corporeal lives and our spiritual lives that helps explain the inner logic of the Sacraments. Specifically he says “the spiritual life is analogous to the corporeal, since corporeal things bear a resemblance to spiritual. Now it is clear that just as generation is required for corporeal life, since thereby man receives life; and growth, whereby man is brought to maturity: so likewise food is required for the preservation of life. Consequently, just as for the spiritual life there had to be Baptism, which is spiritual generation; and Confirmation, which is spiritual growth: so there needed to be the sacrament of the Eucharist, which is spiritual food” (ST III, q.73, a.1). While it is certainly a clever way to teach about the need for the Sacraments, to see it as only that would be to miss an important analogical corollary; one that has practical applications for our apostolic approach to those in various stages of conversion.
In mitigating the factions that had arisen within the Corinthian community, St. Paul reminds them of his (and our) role in the conversion of others. It is by way of cooperation that we participate in the conversion of another, but it is ultimately God Who provides the growth (c.f. 1Cor 3:6-7). We all intuitively grasp this and realize that our role is secondary (at best) and that only through grace does another person “grow to the full stature of Christ” (Eph 4:13). Nothing new has been said so far. But how that growth is provided is not at all intuitive. In fact we might be tempted to think it is a mystery and only according to God’s good pleasure. As Catholics we do know that there is one sure way that God causes growth—through the Sacraments.
Sacramental Inertia
This is where St. Thomas’ analogy between our corporeal lives and our spiritual lives fits in. The analogy is not just about the inner logic of the Sacraments themselves but also represent a progression in our Spiritual lives. Just as a living person has a natural drive toward food, the person who has been born again in Baptism has a supernatural drive to feed on the Bread of Life. Just as the child who has been born and has nourished his life with food desires to grow up, so too in the Spiritual life there is a supernatural desire for Confirmation. What St. Thomas doesn’t say, but which is implied, is that this supernatural desire is contained as a grace within the Sacraments. Baptism leads to a desire for the Eucharist. Baptism and the Eucharist lead to a desire for Confirmation. Baptism and Confirmation lead to an increased desire for the Eucharist. Each reception of the Eucharist leads to a more fervent desire for the Eucharist itself. And so, through this analogy we see that within the Sacraments there are graces pushing the recipient towards the other Sacraments, most especially towards the “source and summit” in the Eucharist. It is like Newton’s first law applied to the Spiritual life—that which is set in motion in Baptism stays in motion through the other Sacraments.
Like all theological truths, this (super)natural progression also has practical consequences, one which we ought to make profit of in our apostolic endeavors. If we know that an infallible means of growth is the Sacraments and follow St. Paul’s model then we ought to push others towards the Sacraments. When we meet someone who does not know God at all and is unbaptized, our focus ought to be to lead them to the Baptismal font. Why? Because the grace of conversion contains within itself a desire to be baptized. If the person is Baptized, then our focus ought to be on pushing them towards Confession and the Eucharist. Why? Because the Baptized person is already being inwardly pushed towards those Sacraments. They may not be able to identify the specific impulses, but they will know them when they see them. Lukewarm Catholic already in communion with the Church? Push them towards Jesus in the Eucharist Who is the fire that will set ablaze the most lukewarm of hearts.
I knew of a man who did nothing else but invite his Protestant friends to Eucharistic Adoration. He reasoned that if his Protestant friends really knew Jesus, they would recognize Him when they met Him in the monstrance. It might not happen immediately, but in many of the cases they kept going with him until it did. If Jesus is really there, and He is, then it is hard to find a flaw in this approach.
Applying the Law Sacramental Inertia
Our apostolic endeavors are only effective insofar as we cooperate with grace already working interiorly in the person. By making use of this principle of Sacramental Inertia we are assured that we are on the same page as the Holy Spirit. The Sacraments become a sort of apostolic blueprint that represent a goal. In Latin, the Mass ends with Ite Missa Est, literally “she is sent,” meaning that we are sent out into the world to bring others back with us. Like John the Baptist our goal is simply to point out and bring others to Jesus. If we really believe the Sacraments are what the Church teaches they are, we will make them our apostolic goals.
One last point merits our attention as well, especially if it seems that the picture I have painted is overly simplistic. It is no coincidence that the Sacraments, especially the Eucharist (and Confession), as next steps are also the biggest obstacles. The principle of Sacramental Inertia is not foreign to mankind’s greatest spiritual foe. They are either mocked by direct attack, counterfeited or else indirectly attacked by attacking the Sacrament of Holy Orders. We should be constantly aware that the last thing the Devil wants is for a non-Catholic to begin a Sacramental life and he will do all that he can to impede that. Our approach, when not leavened with prayer and sacrifice, will always become mere apologetics. The Sacraments are the greatest treasure of the Church and we must always recognize that sharing these gifts is our apostolic goal.