Canon 844/2 of the 1983 Code of Canon Law teaches: “Whenever necessity requires or a genuine spiritual advantage commends it, and provided the danger of error or indifferentism is avoided, Christ’s faithful for whom it is physically or morally impossible to approach a catholic minister, may lawfully receive the sacraments of penance, the Eucharist and annointing of the sick from non-catholic ministers in whose Churches these sacraments are valid.”
But Canons 2316 and 1258 of the 1917 Code of Canon Law forbid this. Canon 2316 provides: “A person who of his own accord and knowingly helps in any manner to propagate heresy, or who communicates in sacred rites with heretics in violation of Canon 1258, incurs suspicion of heresy.” In other words, to go to the Masses of non-Catholics, though these Masses are valid, is to appear to be a heretic, and this appearance is called suspicion of heresy, and Canon 2315 provides: “If a person suspected of heresy, …, does not amend within six months …, he shall be considered as a heretic and be liable to the penalties for heresy.” Canon 1258 tells us: “It is unlawful for the faithful to assist in any active manner, or to take part in the sacred services of non-Catholics.” This is quite clear, the Church does not consider that there is any genuine spiritual advantage to be obtained by going to non-Catholic ministers.
Let us consider the evolution of this new concession after Vatican II. The Decree on Ecumenism of Vatican II states: “On the other hand, participation in divine worship (communicatio in sacris) may not be considered a means to be used indiscriminately for the restoration of Christian unity. Such participation depends on two basic principles especially: the expression of unity of the Church, and the sharing of the means of grace. The expression of unity very often forbids participation but the grace to be sought sometimes recommends it.”
In March 22, 1973 the Bishop of Superior, Wisconsin issued the following letter: “On May 25, 1972, His Holiness, Pope Paul VI, issued a Pastoral Instruction entitled ‘Instruction Concerning Cases When Other Christians May Be Admitted to Eucharistic Communion in the Catholic Church.’ A basic reason for the issuing of this Pastoral Instruction is the fact that there have been a number of changed attitudes and practices within the Church of Christ. In various non-Catholic denominations there has been a considerable shift in sacramental theology.
“In response to this, Pope Paul’s Pastoral Letter gives the following conditions which been to be met for admitting non-Catholic Christians to Holy Communion:
“1. They must believe in the Real Presence of Christ in the Eucharist of the Catholic Church;
“2. They must experience a serious spiritual need; this need is to be understood as a need for an increase in the spiritual life and a need to be incorporated into Christ and united with His members;
“3. They must ask to receive Holy Communion. This means a real desire must be expressed on the part of the non-Catholic Christian.”
The Holy Office on June 22, 1859 declared: “Communication with heretics can be either in a condemned doctrine, or in rites and other signs indicative of adherence to a false sect, with the accompanying scandal of the faithful, to whom the Church therefore forbids this communion, lest the faith be lost or endangered. Whence St. John the Evangelist strictly commands: ‘if anyone comes to you and does not bring this (i.e. the Catholic) doctrine, do not receive him into the house, or say to him, Welcome. For he who says to him, Welcome, is sharer in his evil works., II John 20. These words evidently imply that everything is forbidden that is expressed by a welcome, in so far as it constitutes liturgical actions instituted to signify ecclesiastical unity. Wherefore we read that a law was enacted by the Fathers of the Council of Carthage ‘against praying or singing with heretics’ as is cited by Benedict XIV . It is therefore illicit to invite heretics to a choir during sacred services, to sing alternately with them, to give them peace or sacred ashes and other such tokens of external worship, which are rightly and reasonably regarded as signs of interior bond and agreement. This is to be done neither in the active sense, namely by giving them such things, nor in the passive sense, by accepting from them in their sacred services.”