God makes use of his creation, living and non-living, in order to manifest his power and glory. In the Old Testament, for example, he used a replica of a poisonous snake so that everyone who will look at it will be saved (Numbers 21:8, John 3:14). The bones of Elisha were used by God to revive a dead person (2 Kings 13:21). In the New Testament, he used the bread and wine and made them his body and blood for the salvation of many. In Acts 19, handkerchiefs and aprons were used by God to heal the sick.
These are just some of many Biblical evidences why many sacramentals like blessed medals were developed. Wearing medal is a form of popular piety. Whenever we see someone wearing a religious medal with an image of Jesus or his saints, we immediately assume that he or she is a devout and practicing Catholic.
Even Our Lady of Guadalupe wore a medal of the holy cross when she appeared to Saint Juan Diego in Mexico in 1531. By wearing one, she manifested her own consecration to Jesus Christ, her son and true God, which as we know was crucified on the cross for all.
According the the Catechism of the Catholic Church:
Besides sacramental liturgy and sacramentals, catechesis must take into account the forms of piety and popular devotions among the faithful. The religious sense of the Christian people has always found expression in various forms of piety surrounding the Church’s sacramental life, such as the veneration of relics, visits to sanctuaries, pilgrimages, processions, the stations of the cross, religious dances, the rosary, medals, etc. These expressions of piety extend the liturgical life of the Church, but do not replace it. (CCC 1674-75)
Catholics believe that God is not a God of the dead (Mark 12:27, Luke 20:38) but of the living, for to him all are alive. Catholics understand that the living Church of God is composed of three states: the Church Militant (we who are striving to be holy), the Church Suffering (those who have died in friendship of God and their souls are being purified before entering heaven), and the Church Triumphant (those who are in heaven enjoying God’s company). (CCC 954, Revelation 7)
Catechism 947 states that all the faithful form one body and the good of each is communicated to others. The most important part of the body is Christ-the head of the church-who communicates these goods to all the members. And the saints in heaven, being more closely united to Christ, do not cease to intercede with the Father for us, as they proffer the merits which they acquired on earth through the one mediator between God and men, Christ Jesus (CCC 956, 1 Tim 2:5).
Understanding these basic teachings of the Church will lead us away from the sin of superstition which is the belief that medals and other devotional items and practices have supernatural or magical powers in themselves. This is an insult to God and affects the worship we offer the one and true God (CCC 2111). Wearing a medal is not bad when we attribute all the favors and graces we received through them to God alone.
Medals are instruments that help us recall the mysteries of our Faith. They help us recall the times when God worked with the greatest saints and how they dedicated their lives for God and for his Church. So, by wearing, touching, and looking at their medals, we are inspired to imitate their holy lives. In short, wearing medals of saints or any other medals is one of many ways for us to honor God in the wondrous works he did through his saints.
There are plenty of choices of medals nowadays but the most common ones that Catholics wear are: the St. Benedict medal, the Miraculous Medal, and the patron saints medals. According to the Catholic Encyclopedia, this practice dates back to 1200 when Pope Innocent III granted right to a group clergy the casting of lead medals impressed with an image of the Apostles Peter and Paul. Since then, it has been widely embraced because of the good effects it does to the faithful.
But take note of this fact: the Catholic Church does not oblige her members to own or wear a medal, neither she demands what medal to choose because wearing one is only a devotional act. We must remember that medals, although proven to be helpful to many, they do not guarantee salvation. “Sacramentals do not confer the grace of the Holy Spirit in the way that the sacraments do, but by the Church’s prayer, they prepare us to receive grace and dispose us to cooperate with it” (CCC 1670). Only Christ can assure us salvation. If we ask and let him, he can save our souls through the sacraments he himself instituted.