An interesting article from livingcatholicism.com. Here is an excerpt regarding the Brown Scapular...
Is the brown scapular necessary for salvation? The answer to this question is simple….NO. While all devotions to the Blessed Mother are worthwhile and beneficial the Church has never declared one of them to be necessary as She does the Sacraments, especially Baptism. One might ask what the reason is for this. The answer again is simple….Christ did not command it as He did the living of the Sacramental life.
So why wear the Brown Scapular? Within the Body of Christ, Mary holds a special place. She is the Mother of God. She was assumed into heaven. She is the queen of heaven and earth. For some specific reason God has deemed it necessary for her to intervene for us and to appear to some of us in this life. She counsels us always to pray without ceasing, to return to the Sacraments, to read and study the Scriptures, to be faithful to the Church, and to convert to her Son Jesus. If she has recommended a devotion to us as a means of demonstrating our devotion to her and as a possible means of growing in holiness than it must be worthwhile.
Wearing a brown scapular is meant to be an outward sign of an interior conviction and devotion to Mary. In imitating Mary, we model ourselves ultimately on the one who most perfectly imitated Christ while on this earth.
ARE YOU WEARING YOUR BROWN SCAPULAR?