Because we have Jesus in the Eucharist.
Because we have the Holy Trinity.
Because we have Mary as our Mother.
Because we have the stories of the Saints.
Because we are the only Church founded by Jesus Christ.
Because we are Universal.
Because we have the Mass.
Because we celebrate Mass daily.
Because we put the bible together.
Because we have brother and sisters in religious orders.
Because we have purgatory.
Because we are One Holy Catholic Apostolic Church.
Because we have the true apostolic succession.
Because we have relics.
Because we have the Sacraments.
Because we have Incorruptibles.
Because we have the true cross and bones of all the past popes.
Because we have the priesthood.
Because the Vatican is the smallest country in the world but has the most power.
Because we are the only church that was promised by Jesus that it would not fail.
Because we have Eucharistic miracles.
Because I'm Catholic!
-AVM
