The inscription on the cross is common of a Saint Benedict Medal
Eius in obitu nostro praesentia muniamur
May we be strengthened by his presence in the hour of our death
And the person in Biblical Dress is probably St. Benedict of Nursia, the founder of the Benedictine Order, an ancient order of religious brothers from Italy.
Unless the liquid contained in it was blood, it's likely as not that it contained Holy Water.
It might well be a 3rd degree relic (i.e. a sacramental touched to a 1st degree relic), but it's clearly a sacramental of some sort (i.e. a blessed item; not something that should be sold). I wouldn't think there'd be any reason to have an unblessed container of liquid in a holy medal.