I’d say
everything that the Catholic Church teaches is essential and necessary to be believed and followed to be a true-blue, 100% Christian
as desired by Jesus Christ.
From *Lumen Gentium, *the Dogmatic Constitution on the Church of VC II, #8:
This is the one Church of Christ which in the Creed is professed as one, holy, catholic and apostolic, which our Savior, after His Resurrection, commissioned Peter to shepherd, and him and the other apostles to extend and direct with authority, which He erected for all ages as “the pillar and mainstay of the truth”.
This Church constituted and organized in the world as a society,
subsists in the Catholic Church, which is governed by the successor of Peter and by the Bishops in communion with him, although many elements of sanctification and of truth are found outside of its visible structure. These elements, as gifts belonging to the Church of Christ, are forces impelling toward catholic unity.
So, for example, the Orthodox would be excluded from belonging in perfect communion to “the one Church of Christ”, unlike the Latin Church and all of the Eastern Catholic Churches, because they consist of schismatic groups that do not have Peter as their head, and Jesus gave us Peter and his successors to be His vicar, the head of the Church on earth, and the rock on whom the Church is built, who can not err when speaking in an official pronouncement on faith or morals. Are the Orthodox “governed by the successor of Peter and by the Bishops in communion with him”? No, so they are
deficient Christians. Anglicans and Lutherans are much more deficient, lacking the Sacraments, and then follows the Baptists, etc., ending with today’s “non-denominationalist” storefront- or mega-churches. The order goes pretty much exactly according to the time they were formed, from the 16th century to the 21st. Speaking absolutely, in absolute terms (absolutely) I’d say that nothing is absolutely necessary if one dies before reaching the age of reason. So, since people do actually die before reaching the age of reason, nothing is
absolutely essential for entering heaven. For adults, there is only one thing
absolutely essential for entering heaven - following one’s conscience and living the best as one knows how. Through genuinely invincible ignorance and God’s mercy, some
may be (maybe) saved who are not Christian, followers of other religions, or maybe followers of no religion at all. We place them in God’s merciful hands. He created them and loves them. As to who is able to be even considered a Christian, only one thing is
absolutely necessary - #4 above. An infant who is baptized is a Christian. God has claimed the person for Himself, removed Original Sin, given him Sanctifying Grace, and made him a co-heir with Christ. If one is baptized as an adult, then #1-3, along with contrition for all one’s sins and also a profession of faith in all that the One, Holy, Catholic, and Apostolic Church teaches must be present to
be baptized. This is what the long period of catechesis is for. Must this profession be present in an
absolute sense? No, see Canon IV below. So what must
absolutely be present at baptism? I’d say #1-3 and repentance for all one’s sins. Such a person
could claim to be a Christian and
could be saved, in the sense of entering heaven after living a normal lifespan (everyone is perfectly, 100%, completely “saved” at baptism), but living outside the visible bounds of the Church, and thereby being excluded from rather important things such as
The Truth and
The Seven Sacraments instituted by Christ, most especially the Holy Eucharist and Holy Confession, is it likely? I don’t know. I’ll leave that question alone and just place them in the merciful hands of God, who is the judge of all souls.
From the Council of Trent:
Canon IV. If any one saith, that the baptism which is even given by heretics * in the name of the Father, and of the Son, and of the Holy Ghost, with the intention of doing what the Church doth, is not true baptism; let him be anathema.
Canon V. If any one saith, that baptism is free, that is, not necessary unto salvation; let him be anathema.
Canon VII. If any one saith, that the baptized are, by baptism itself, made debtors but to faith alone, and
not to the observance of the whole law of Christ* [the true knowledge of which only exists in the Catholic Church]; let him be anathema.
Canon VIII. If any one saith, that the baptized are freed from all the precepts, whether written or transmitted, of holy Church, in such wise that they are not bound to observe them, unless they have chosen of their own accord to submit themselves thereunto; let him be anathema.
My :twocents: :shamrock2: