Anyone may convert to Catholicism if they accept the basic articles of faith in the Nicene Creed, and the Catechism of the Catholic Church. The route to conversion in this day and age is via the Rite of Christian Initiation of Adults (RCIA) RCIA is not for the baptized; it is for the unbaptized, and can be adapted for non-Catholic Christians who wish to be initiated into the Catholic Church.