It’s not really a question of infallible teaching per se. The prohibition has been based on some basic principles:
- Divorce does not end a valid marriage (neither does an annulment, it recognizes that no marriage happened in the first place)
- One cannot enter a new marriage while still in a valid previous marriage
- Sexual intercourse between married persons with those who are not their spouse is the sin of adultery
- “Remarriage” (without a declaration of nullity) while a persons first spouse still lives generally include ongoing acts of adultery
- Adultery is grave matter unto the point of mortal sin that loses saving grace
- Receiving the Eucharist in the state of mortal sin is sacrilegious and must be answered to before the Lord
- The sin of adultery can be forgiven in confession if, and only if, there is firm intent to avoid committing the sin again
Those understandings are at the core of our understanding of the divine nature of marriage, sexual sin and worthy reception of the sacraments. They underpin much of the framework of the faith.
The challenge for many is that recent statements seem to imply that it is possible for someone to enter into a new “marriage”, but have reduced culpability that might make it grave matter, but not a mortal sin. For many of the faithful, both clergy and laity alike, is how to square that thought with Christ’s own teachings on Divorce and Remarriage. It turns on it’s head some very basic teachings of the Church. It appears to set aside our understanding of what Christ taught and places mercy as more important than following what God has revealed to us.
As a protestant convert, it causes me some consternation as it feels a little like returning to my protestant roots where we had principles that always allowed exceptions to the rules. In the 35 years I was a protestant, I saw many exceptions become the norm and the principles be cast aside as un-achievable. If that same thought process invades Catholic teaching, then Her claim to uphold the unchanging Truth of God becomes suspect.
If remarriage no longer involves adultery then what other teachings of Christ can be set aside for pastoral mercy? How long until the exception becomes the rule? I have already seen my church of origin slough off inconvenient teachings to conform itself to the world and I don’t relish the idea of the Catholic Church doing the same. I came to the Church with faith that Her teachings were a solid island in a stormy sea of moral relativism, but without clarification on the unified teachings of the Church I wonder just how stable that moral rock is.
The confusion comes form different bishops putting forth guidelines that seem at odds with each other. If one cannot receive in Dioceses X, but their culpability is reduced in Diocese Y 30 miles away, then how can we claim to follow a universal faith?