St. Louis de Montfort recommends wearing little chains to symbolize a person's consecration to Jesus through the Mary.
At the end of St. Louis de Montfort’s True Devotion to Mary, he suggests the wearing of little chains to remind a person of their consecration to Jesus through Mary.
It is not a requirement of the devotion, as he notes, “It is perfectly true, these external tokens are not essential and may very well be dispensed with by those who have made this consecration. Nevertheless, I cannot help but give the warmest approval to those who wear them.”
He then proceeds to list several reasons why the wearing of little chains can benefit a person’s soul consecrated to Jesus through Mary.
1Reminder of baptism
These little chains are a wonderful aid in recalling the bonds of sin and the slavery of the devil from which baptism has freed him. At the same time, they remind him of the dependence on Jesus promised at baptism and ratified when by consecration he renewed these promises. Why is it that so many Christians do not think of their baptismal vows and behave with as much licence as unbelievers who have promised nothing to God? One explanation is that they do not wear external sign to remind them of these vows.
2Outward sign of being a servant of Jesus
These chains prove they are not ashamed of being the servants of Jesus and that they reject the deadly bondage of the world, of sin and of the devil.
3Protection against the Devil
They are a guarantee and protection against enslavement by sin and the devil. For we must of necessity choose to wear either the chains of sin and damnation or the chains of love and salvation.
While many wear these little chains on their wrists, some wear them underneath their socks around their ankles, or others may wear a more stylized chain as a necklace.
Simply put, the chain is an outward reminder of a person’s commitment to live a life of holiness, ensuring that they do not forget the promises they made to God.