[quote=USMC]Taking part in a non-Catholic service is and alway will be a sin against the first commandment. Catholics are still not allowed to take active part in a non-Catholics services. There are no exceptions with regard to Protestant services (since they do not have valid sacraments)…
Let’s not overstate, please. Protestant baptism is valid: “Baptism by immersion, or by pouring, together with the Trinitarian formula is, of itself, valid. Therefore, if the rituals, liturgical books or established customs of a Church or ecclesial Community prescribe either of these ways of baptism, the sacrament is to be considered valid unless there are serious reasons for doubting that the minister has observed the regulations of his/her own Community or Church.”
Therefore, “Catholics may, in common celebration with other Christians, commemorate the baptism which unites them, by renewing the engagement to undertake a full Christian life which they have assumed in the promises of their baptism, and by pledging to cooperate with the grace of the Holy Spirit in striving to heal the divisions which exist among Christians.”
[quote=USMC]Regarding a Protestant service, a Catholic can never take active part in a Protestant service, but is allowed to attend a wedding, or funeral, provided they are not taking an active part in the service.
Again, let’s not overstate. I, as a Catholic, for example, can be a godparent to my Lutheran nephew.
Furthermore, “Christians may be encouraged to share in spiritual activities and resources, i.e., to share that spiritual heritage they have in common in a manner and to a degree appropriate to their present divided state.”
“The term ‘sharing in spiritual activities and resources’ covers such things as prayer offered in common, sharing in liturgical worship in the strict sense,…as well as common use of sacred places and of all necessary objects.”
Catholics are generally forbidden to participate in non-Catholic sacramental worship, but not liturgical worship. “By liturgical worship is meant worship carried out according to books, prescriptions and customs of a Church or ecclesial Community, presided over by a minister or delegate of that Church or Community. This liturgical worship may be of a non-sacramental kind, or may be the celebration of one or more of the Christian sacraments. The concern here is non-sacramental worship.”
For further reading, visit here please.
– Mark L. Chance.