Everyone is welcome to attend a Catholic Mass. However, a non-Catholic’s participation in the Mass does not include reception of Holy Communion. Here are some guidelines for receiving Holy Communion in the Catholic Church:
For our fellow Christians:
We welcome our fellow Christians to this celebration of the Eucharist as our brothers and sisters. We pray that our common baptism and the action of the Holy Spirit in this Eucharist will draw us closer to one another and begin to dispel the sad divisions which separate us. We pray that these will lessen and finally disappear, in keeping with Christ’s prayer for us “that they may all be one” (Jn 17:21).
Because Catholics believe that the celebration of the Eucharist is a sign of the reality of the oneness of faith, life, and worship, members of those churches with whom we are not yet fully united are ordinarily not admitted to Holy Communion. Eucharistic sharing in exceptional circumstances by other Christians requires permission according to the directives of the diocesan bishop and the provisions of canon law (canon 844 § 4). Members of the Orthodox Churches, the Assyrian Church of the East, and the Polish National Catholic Church are urged to respect the discipline of their own Churches. According to Roman Catholic discipline, the Code of Canon Law does not object to the reception of communion by Christians of these Churches (canon 844 § 3).
For those not receiving Communion:
All who are not receiving Holy Communion are encouraged to express in their hearts a prayerful desire for unity with the Lord Jesus and with one another.
We also welcome to this celebration those who do not share our faith in Jesus Christ. While we cannot admit them to Holy Communion, we ask them to offer their prayers for the peace and the unity of the human family.
Members of the Orthodox churches and the Polish National Catholic Churches share a more intimate bond with us, however. They may receive the Eucharist when they ask for it and they are properly disposed (cf. Canon 844).
Article: ”Approaching the Catholic Church...for the first time!”: http://www.leaflets.on.ca/leafapp.htm
How to Become a Catholic:
God bless you!