Through baptism we are incorporated into the Body of Christ (i.e. the Church). We are put into communion with the Church through our baptism. Communion with the Church isn't "all or nothing", however. A person can be in imperfect communion with the Church. "For men who believe in Christ and have been properly baptized are put in some, though imperfect, communion with the Catholic Church." (CCC
1271. That is so if they "do not profess the Catholic faith in its entirety or have not preserved unity or communion under the successor of Peter." (CCC
838). See also CCC
855.
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