How does an unlearned person know if Catholic Church or Orthodox is true?

I was reading about the differences between the churches and there are several like theoria vs philosophical speculation. Orthodox say that the superior way that doctrine and truths of God are validated is through theoria, the experience of God and his uncreated light, while Catholics arrive at them through philosophical speculation like that of Augustine and Aquinas. And if that’s true the Orthodox view seems more authentic to me, that God is known through experience of Him, and not philosphical reason, bit anti-intellectual and placing spirituality higher than philosphy. So Orthodox do believe that Catholics err and are incorrect with issues like forbidding contraception? But, I want to know, if religion is not just picking and choosing what doctrine suits you best, how does one know which church is telling the truth? I’m actually considering if Orthodoxy might be the true church.

I will let St. Optatus speak, writing against the Donatist schism…sometime in the AD300s…

St. Optatus’s Against the Donatists is composed of seven books (see the table of contents). After laying out the history of the schism in Book One, he turns in Book Two to the question: “Which is the One True Catholic Church and Where is it to be Found?” In what may be the most important and revealing statement in the whole of his work, he writes:

For it was not Caecilian who went forth from Majorinus, your father’s father,12 but it was Majorinus who deserted Caecilian; nor was it Caecilian who separated himself from the Chair of Peter, or from the Chair of Cyprian — but Majorinus, on whose Chair you sit — a Chair which had no existence before Majorinus himself.13

How does St. Optatus show that the Catholic Church did not go out from the Donatists, but that the Donatists went out from the Catholic Church? He does so by way of the Chair of St. Peter. The bishop that remains in communion with the Chair of St. Peter in Rome is the bishop who has remained with the Catholic Church. In this particular case, the bishop of Carthage who had remained in communion with the bishop of Rome, was Caecilian and his episcopal successors in Carthage. The bishop who has broken communion with the Chair of St. Peter is the bishop who is in schism from the Catholic Church. Therefore the bishop in Carthage who had broken fellowship with the Chair of St. Peter in Rome, was the bishop in schism from the Catholic Church. In this way St. Optatus shows that because Majorinus and his episcopal successors (and all the laypeople who followed them) had broken fellowship with the Chair of St. Peter, therefore they were the ones who had gone out from the Catholic Church, and were presently in schism from the Church.

Later in the work he shows that St. Peter, the Head of the Apostles, was the first to occupy the Episcopal Cathedra in Rome, and that the purpose of this Cathedra was to preserve unity among all Christians, including even the other Apostles. He writes:

You cannot then deny that you do know that upon Peter first in the City of Rome was bestowed the Episcopal Cathedra, on which sat Peter, the Head of all the Apostles … that, in this one Cathedra, unity should be preserved by all [in qua unica Cathedra unitas ab omnibus servaretur], lest the other Apostles might claim each for himself separate Cathedras, so that he who should set up a second Cathedra against the unique Cathedra would already be a schismatic and a sinner. Well then, on the one Cathedra, which is the first of the Endowments, Peter was the first to sit.25

You should pray much.
You should go and speak with Catholic and Orthodox priests, and also attend their religious services. Pray and seek the truth.
This is very like what I went through myself 50 years ago.

When I was in your shoes several years ago, I had a catholic priest tell me point blank that if I went eastern orthodox instead of catholic I would not be going wrong. A close friend of mine who went east but was still at the point of decision was told by an orthodox priest essentially the same thing about going catholic.

The Catholic church does not say that the Orthodox are in full communion but they do say that their sacraments are valid. That is a significant statement.

Personally I found the Catholic faith to be the true faith. The bishop of rome has always had a place of honor in the church. The dispute is about precisely how much honor and how far his authority reaches. That quickly descends into a dispute among bishops. I am not a bishop I am a humble believer. I am in the west, therefore I am western. If I was in the east I would have been orthodox. When the bishops want to all kiss and make up then we’ll all eat at the same altars. And an incredible amount of progress has been made since the mid 1900s, much remains.

Be docile to the promptings of the Holy Spirit.


The Catholic Church believes (and always has since the time of Peter) that Christ will protect the Church from errors in Faith and Morals.

Let’s use Artificial Birth Control (ABC) as an example:
ABC wasn’t something new in the 1960s. Yes, it was a new method using a new chemical, but there were birth control methods during the time of Christ.

The fact that the Church always condemned ABC (even before the schism) and now some of the Orthodox think it’s OK should be proof that they are the ones who have strayed.

The True Church is the one in Communion with Peter.

Granted, this is Wikipedia, the article is very interesting:

Also, check out

Sense all of the Orthodox are not in communion with each other, which Orthodox are you considering to be true?


Well all Catholics are not in communion with each other. Not sure what the point of your question is.

Where is Peter? You can’t be the successor of Peter if you don’t hold the faith of Peter. And I would love to see all the patristic support for NFP. All of the condemnation of ABC applies equally to NFP. :wink:

My answer as a Catholic would be that the Eastern Orthodox Churches are true Churches. As Pope Benedict commented though, they do “lack” something in that they are not in communion with Rome. In terms of spirituality, the West also has strong traditions. If you find that Eastern Spirituality is important to you, why not check out the Eastern Catholic Churches? They are both in communion with Rome and are part of the venerable eastern spiritual tradition. :thumbsup:

Any group not in communion with the Catholic Church is not Catholic but we don’t own the word “Catholic”. I assume you will say the same with the Orthodox, right? So which Orthodox is the true Orthodox Church, EO or OO? The OP may want to know this bit of information to make a sound decision. If the OP is now unsure, because of your comment, which “Catholic” church he/she was originally referring to let he/she speak up please.


So the groups the Catholic Church says has “valid” sacraments, such as the Old Catholic Churches, are not Catholic? What about the SSPX?

Nice dodge lol, just ignore the fact the Orthodox (and every other non-Catholic religion that calls itself Christian) have capitulated on ABC despite formerly opposing it and contributed to the mentality behind the abortion holocaust because they have no solid moral theology.

No dodge. Just pointed out you, by your own standards, have capitulated as well.

It’s a simplification, that has truth to it, but is not wholly accurate. Mysticism is not left in the cold in Catholicism. Philosophy is not left in the cold in Orthodoxy. Just read the letters of St. Paul, and there you will find both.

They are what they say they are. If you want to know if they are “Catholic” as in, in communion with the Bishop of Rome, you will have to ask them. That would be the “Catholic” I am, the same one generally referred to on this forum with out confusion, and that I assumed the OP was referring to in the OP. If not I await his/her clarification.


most of all, Pray for discernment continually. And after 3 days, while continuing praying for discernment, then select one and then live out that Faith exclusively for a set period time* in its fullness with a spiritual father guiding you, prayers, services, fasting, catechism, etc.

*Traditionally catechumens would live the Faith for 3 yrs before they made a decision and were permitted to join.

If after the set period of time, if you just “know” than continue in that Faith and join and begin receiving Communion, but if you still have any hesitation then for the same set of time live out the other faith continuing to ask for discernment.

When you’re living out the faith ask yourself if you are being changed for the better, is it challenging you to become more holy, inspiring you to strive for perfection while recognizing how far you are, is it rooting out sin?

You’re not alone. Many have been in your shoes.

Good thing NFP isn’t artificial contraception or you might have a point.

Sure it is. It certainly has the exact same purpose, to enable a couple to have intercourse without getting pregnant. I have to say this whole question is kind of silly. To say that using a condom to prevent pregnancy is sinful, but using this…

Is natural is pretty absurd.

NFP uses can be three-fold: can be used to prevent pregnancy OR to achieve pregnancy AND to discover early, help doctors diagnose & treat, a wide array of diseases or defects within a woman’s body.

In the Catholic Church all three uses are permissible. In the Orthodox Church the latter two would always be permissible. Some Orthodox Bishops permit non-abortive forms of birth control, including NFP, while others only allow for it’s use if the spiritual father deems it necessary to provide a blessing for it and some Bishops don’t permit any form of birth control.

But you have a point, is it natural or rather are the use of thermometers to determine marital relations natural?

I don’t know the history of thermometers…when they were invented & were they used for this purpose like this before or during or immediately following Christ’s physical life on earth? Or is this totally brand new?

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