Objection: "How this isn't idolatry by putting your faith in an object (medal) instead of God?".
Reply to Objection: "When she had heard of Jesus, came in the crowd behind him, and touched his garment. For she said: If I shall touch but his garment, I shall be whole. And forthwith the fountain of her blood was dried up... she was healed of the evil... And he said to her: Daughter, your faith has made you whole" (Mark 5:27-29,34).
Thus putting your faith in an object that is in touch with Jesus Christ (Jesus' garment) or is blessed by Jesus Christ (Miraculous medal) is putting your faith in Jesus Christ as the Gospel woman shows us.
+ the only medal whose design was made by The Blessed Virgin Mary Herself, The Mother of God and due to that* of everyone and everything, grace and salvation included
* - nothing exists outside infinity i.e. God
+ the words of The Blessed Virgin Mary were:
"Have a medal struck upon this model, persons who wear it indulgenced, will receive great graces, especially if they wear it around the neck; graces will be abundantly bestowed upon those who have confidence.";
and "those who wear it indulgenced, and repeat this prayer** with devotion, will be, in an especial manner, under the protection of the Mother of God."
** - The Miraculous Medal prayer is written on The Miraculous medal: "O Mary conceived without sin pray for us who have recourse to you!"
+ 'indulgenced" means that the medal is blessed by a Catholic priest so that a Catholic can obtain indulgences (forgiveness not of sins but only of all debts of punishment for sins if he is in God's grace) from infinite treasury of The Church due to The Medal;
to obtain such an indulgence he obviously must believe it first and then, in confidence, fulfill all the other necessary conditions prescribed for gaining of indulgence (can be found in every Catholic prayer-book)
+ The Miraculous medal was called 'Miraculous' by humans who wore it and/or witnessed humanly unexplainable recoveries from humanly incurable diseases and in other humanly hopeless cases
+ The Medal is for all humans because the promises use general expressions 'persons' and 'those who' and not 'Catholics' or 'Catholics who'.