Juniper —

If a baptized Protestant, assuming the Baptism was valid, enters the Church, they will need to confess their sins (as best they can remember), as part of the process of being received into full Communion with the Church.

For a Baptist that means, after instruction in the faith, they will first go to Confession, then receive the Sacrament of Confirmation, and Holy Communion.

John
[Related Posting] On Valid and Invalid Baptisms