You shall know them by their fruits: Mary and the Fruits of the Spirit

“By their fruits you shall know them.” – Matthew 7:16The criterion of fruits, “by their fruits you shall know them,” is one of the most practical hermeneutical principles of the Gospel. Inserted within the context of the warning against false prophets (Matthew 7:15-20), the criterion of fruits offers a method of discernment that does not depend on access to the inner person but is verifiable externally: the effects of action over time, the quality of relationships, and the consistency between what is preached and what is lived. It is a criterion that is both humble (it does not judge intentions, inaccessible from the outside) and demanding (fruits manifest what the tree is).The botanical image is simple yet precise: grapes do not grow on a vine by decree. Figs do not come from a fig tree through effort of will. Fruits are the natural expression of what the tree is, determined by its roots, its nature, and the soil in which it is planted. The metaphor applies to spiritual and moral life: the acts people perform over time, their consistent choices, their relationships, and the effects of their influence on others reveal what they are interiorly more reliably than words or appearances. A long series of bad fruits reveals a tree with problems at its roots. A long series of good fruits indicates a healthy tree, regardless of external appearance.I. False Prophets: The Criterion of FruitsThe “false prophets” referred to in Matthew 7:15 are described as “wolves in sheep’s clothing,” an image of disguised danger that resonates particularly strongly in contexts where religious appearance does not correspond to inner reality. In the original context, they likely referred to religious leaders whose teaching or behavior deviated the community from the path of the Gospel. Church history has repeatedly shown that the problem of false prophets—charismatic leaders, influential teachers, prophets of novelties—is permanent and not exclusive to any era.The criterion of fruits as a method of discernment offers invaluable practical wisdom: it allows for evaluation without access to the inner person, without presuming to know their intentions. “Do not judge” (Matthew 7:1) and “know by their fruits” (Matthew 7:16) are complementary instructions: do not judge the interior (inaccessible), but observe the fruits (verifiable). This complementarity avoids two opposite extremes: precipitate judgment on intentions and naivety before documented effects. A leader whose teachings consistently produce fear, dependence, rupture with family, and isolation from a broader Christian community reveals, by their fruits, a problematic “tree,” regardless of declared intentions.

Ignatius of Loyola’s Criteria for Discerning Spirits

Ignatius of Loyola applied the criterion of fruits specifically to spiritual discernment: a spirit that initially brings “consolation” but, over time, leads to desolation, rigidity, and isolation is identified as a “bad spirit” by its fruits. The Ignatian criteria are not about initial enthusiasm, which both good and bad spirits can produce, but the trajectory over time. This temporal perspective is crucial: fruits need to mature to be visible. Just like a fig tree may look healthy in March and reveal in August that it bore no fruit, patience is part of the discernment process.

Vatican II and Charisms

Vatican II, in *Lumen Gentium* 12, recognized charisms as gifts of the Holy Spirit for the building up of the Church, but emphasized that these gifts should be discerned “by their shepherds.” The criterion for discernment is precisely the fruits: genuine charisms build up the community, serve the poorest, and promote ecclesial unity. Pseudo-charisms that divide, create dependency, and replace sacramental experiences with emotional ones reveal themselves through their fruits, even when accompanied by extraordinary phenomena that mislead superficial discernment.

II. Fruits of the Good Tree: Gal 5 and Mt 7

Paul, in Galatians 5:22-23, listed the “fruits of the Spirit”: “love, joy, peace, patience, kindness, generosity, faithfulness, gentleness, self-control.” This listing serves as a key for reading the criterion of fruits from Matthew 7. Understanding what are good fruits allows the application of the discernment method. The fruits of the Spirit share a relational quality—they are all expressions of love directed towards others—and a durability quality: they are not fleeting emotional states but stable dispositions that manifest in both difficult and easy situations.The contrast with “fruits of the flesh” (Gal 5:19-21), such as “immorality, impurity, sensuality, idolatry, sorcery, hostility, strife, jealousy, fits of rage, self-importance, factionalism, envy, drunkenness, orgy,” is revealing. The fruits of the flesh are essentially divisive and self-referential. The fruits of the Spirit are unifying and other-referential. The “good tree” bears fruits that build relationships and community. The “bad tree” produces fruits that destroy relationships and fragment the community. This pastoral question, “Does this build or destroy the community?” is a practical application of the Mt 7 principle to spiritual discernment.The Carmelite spiritual tradition identified specific “fruits of the Spirit” for contemplative life: interior peace, detachment, and active charity towards others. John of the Cross emphasized that authentic mystical states always produce greater humility, greater charity, and greater fidelity to common duties, never spiritual arrogance, contempt for the “simple,” or neglect of daily responsibilities. Extraordinary states (visions, locutions, ecstasies) are the least reliable as criteria for authenticity. The ordinary, durable fruits of charity are the most secure.

The Franciscan Tradition and the Fruits of Joy and Brotherhood

The Franciscan tradition, in line with the spirituality of its founder, has emphasized the fruits of joy and brotherhood as signs of the Spirit. Saint Francis of Assisi, whose fruits included a universal fraternity that transcended social and religious boundaries of his time, is one of the most eloquent examples of a “good tree known by its fruits.” The stigmata (the most spectacular sign) was not the primary criterion for the authenticity of his charism; it was the friars who converted, the lepers who were embraced, and the Church that was renewed. Enduring fruits are the most reliable measure.

III. Mary, Good Tree: The Fruits of the Fiat

Mariology applies the criterion of fruits in a paradoxical and captivating way: the fruits of Mary are the fruits of someone whose “yes” generated the Excellence Fruit, Christ Himself. The image of Mary as a “good tree” that produced the most perfect fruit in human history is used by patristic tradition: Bernard of Clairvaux described Mary as the “branch of Isaiah” (Is 11:1: “A shoot will come out from the stem of Jesse, and a branch will spring up from his roots”), the tree that sprouted from Jesse’s trunk and produced the Flower that is Christ. In this image, the “fruits” of Mary are not merely human virtues but the fertility of the “fiat”: God’s Son entering history through His availability.The fruits of Mary’s life, visible in the Gospels and the history of the Church, are precisely the fruits of the Spirit listed in Galatians 5. The Magnificat is a poem of joy (“My soul exults in God”). The Visitation is an act of love and service without calculation. Her presence at the Cross demonstrates faithfulness and meekness in extreme suffering. Her intercession at Cana shows patience and kindness toward the hosts’ weakness. Her presence in the Cenacle is peace and loyalty to the community of disciples. Each evangelical scene of Mary is a verifiable “fruit”: concrete behavior, not just declared intention.Popular devotion to Mary ultimately recognizes her fruits: not uncritical acceptance of hagiographic narratives but acknowledgment that her influence on the lives of millions over two millennia has produced verifiable fruits of love, peace, conversion, and service. Marian shrines, such as Lourdes, Fátima, Guadalupe, Czestochowa, are collective fruits: places where the memory of Mary fostered communities of faith, charitable works, and pilgrimages of hope. The criterion of fruits also applies to Marian devotion: when it produces active love, conversion, service, it is a sign of a good tree. When it leads to superstition, passivity, or substitution of Christ, it is a deviation.John Paul II’s Marian theology, particularly in Redemptoris Mater (1987) and Mulieris Dignitatem (1988), applied the criterion of fruits to Marian devotion as a criterion of authenticity: Mary’s devotion is authentic when it leads to Christ, activates charity, and sustains discipleship. The “fruit” that Marian devotion should produce is the disciple following Jesus, the same fruit that Mary’s tree produced: the Son she showed to the world in the stable at Bethlehem, at Cana, and on the cross.IV. Spiritual Discernment in the ChurchThe criterion of fruits has urgent application today in the context of religious and cultural polarization across Christian churches. Charismatic movements, prayer groups, new communities, diverse theological currents all claim evangelical authenticity, often entering tension with one another. The criterion of fruits offers a method of discernment that transcends ideological preferences: not “is this group aligned with my theology,” but “what fruits does this group produce in the lives of its members and in the wider Church?”Discernment through fruits demands time and humility. Time, because fruits take time to ripen. Initial enthusiasm can be misleading, and only perseverance reveals a tree’s nature. Humility, because the criterion of fruits can be applied to oneself: “what fruits does my life of faith produce? Am I becoming more loving, more merciful, more available, or harder, more judgmental, more self-referential?” Authentic spiritual discernment begins in the mirror of one’s own life, not in evaluating others’ lives.Mary’s figure functions in eclesiastic discernment as a stable point of reference: she is, in tradition, the model of the faithful who produces fruits because of whom she received in her heart, not through her own effort. Mary’s fertility, her ability to produce grace-filled fruits for the world, does not result from her initiative but from her availability: she was “the chosen vessel” that God filled, the “tree” whose roots were immersed in God’s promise to Israel and in the Holy Spirit’s reception. The criterion of fruits, applied to Mary, confirms that the source of good fruits is always union with God, not human capability, but human availability to divine gift.Jesus’ instruction, “by their fruits you shall know them,” is ultimately an instruction of hope: fruits are verifiable, reality is not entirely opaque, grace leaves marks. In times of confusion and polarization, when religious discourses multiply and contradict each other, the simple yet demanding question about fruits, “what does this produce in love, peace, unity, service?” is a criterion Jesus himself offered and that Marian tradition confirms: a good tree produces good fruit, and these fruits are the most reliable sign of the Spirit’s presence.