So I think it important every time we refer to doctrine, that we acknowledge all the doctrine acknowledged in Amoris Laetitia, but recognize that some theologians go further in what they believe doctrine is. They may not be right. The “practice” that St. John Paul outlined for divorced and remarried as a practice, was not said to be doctrine. I do not care to go once again into the logic employed to make it doctrine. If anyone ever finds where it has been defined as doctrine, then that would refresh my interest so I could re-evaluate my position. Likewise, the annulment system of tribunals is not a doctrine and, again, I have never had anyone show otherwise.
Familiaris Consortio 84 states:
“However, the Church reaffirms her practice, which is based upon Sacred Scripture, of not admitting to Eucharistic Communion divorced persons who have remarried. They are unable to be admitted thereto from the fact that their state and condition of life objectively contradict that union of love between Christ and the Church which is signified and effected by the Eucharist. Besides this, there is another special pastoral reason: if these people were admitted to the Eucharist, the faithful would be led into error and confusion regarding the Church’s teaching about the indissolubility of marriage.”
So yes, he uses the word “practice”, but the practice is “based upon sacred scripture” and is consistent with the constant teaching and doctrine regarding the Sacrament of Matrimony and its indissolubility. Practice does not contradict Doctrine or past/present teaching. The prohibition on Communion for civilly remarried Catholics who habitually continue to engage in sexual activity conveys a consistent teaching that sex outside of marriage is never permissible, being against the explicit commandments of God himself:
You shall not commit adultery - Exodus 20:14
“Which ones?” the man asked. Jesus answered, “‘Do not murder, do not commit adultery, do not steal, do not bear false witness" - Matthew 19:18
(Jesus speaking) You have heard that it was said, ‘Do not commit adultery. But I tell you that anyone who looks at a woman to lust after her has already committed adultery with her in his heart. If your right eye causes you to sin, gouge it out and throw it away. It is better for you to lose one part of your body than for your whole body to be thrown into hell. And if your right hand causes you to sin, cut it off and throw it away. It is better for you to lose one part of your body than for your whole body to depart into hell. - Matthew 5:27-30
This has been consistently taught for 2,000 years. It remains codified in the Catechism of the Catholic Church paragraph 1650:
"Today there are numerous Catholics in many countries who have recourse to civil divorce and contract new civil unions. In fidelity to the words of Jesus Christ - “Whoever divorces his wife and marries another, commits adultery against her; and if she divorces her husband and marries another, she commits adultery"160 the Church maintains that a new union cannot be recognized as valid, if the first marriage was. If the divorced are remarried civilly, they find themselves in a situation that objectively contravenes God’s law. Consequently, they cannot receive Eucharistic communion as long as this situation persists. For the same reason, they cannot exercise certain ecclesial responsibilities. Reconciliation through the sacrament of Penance can be granted only to those who have repented for having violated the sign of the covenant and of fidelity to Christ, and who are committed to living in complete continence.”
If we commit mortal sin we are obliged to seek Absolution in the Sacrament of Confession before receiving the Eucharist:
“CANON XI.-lf any one saith, that faith alone is a sufficient preparation for receiving the sacrament of the most holy Eucharist; let him be anathema. And for fear lest so great a sacrament may be received unworthily, and so unto death and condemnation, this holy Synod ordains and declares, that sacramental confession, when a confessor may be had, is of necessity to be made beforehand, by those whose conscience is burdened with mortal sin, how contrite even soever they may think themselves. But if any one shall presume to teach, preach, or obstinately to assert, or even in public disputation to defend the contrary, he shall be thereupon excommunicated.” - From the thirteenth session of the Council of Trent, on The Most Holy Sacrament of the Eucharist.
You are of course entitled to your personal opinions. Free will is a cornerstone of Christianity. But you are wrongly making a
generalised comment on the fact that
some aspects of Christianity are open to debate and interpretation, and using that as a justification for stating that the Church’s
specific teachings on sex outside of Marriage, the indissolubility of a Sacramental Marriage and the need for a firm purpose of amendment in or to have a valid Confession must therefore similarly be up for debate.