I think, believe, that all the different denominations have the idea, view, that they have it all correct.
They are all working in a state of good faith that they are presenting the truth to their congregations. Despite their errors.. and differences in opinions....
If they preach "Christ crucified" and that He is the one way to the Father... Then I believe that the majority of the congregation is going to have the right message to guide them to salvation.
Thus... I would consider them to be part of the body of Christ and included in the Church proper.
I generally like what you wrote, but to say that other denominations that the idea that they have it all correct seems to imply that your/our congregation does have it all correct!!
If Jesus Christ is indeed our Teacher and since it is written that He reproves those He loves, then we must know that we (none of us) have it all correct!!!
Still, there is something they must have correct to be a "Christian" and that something is the fundamental part of Christianity - which seems to be what the thread is about.
That fundamental thing is Jesus Christ Himself!!!
Simply put, we are Christians because we believe in Jesus Christ. We might not, and do not have all things figured out correctly, otherwise Jesus Christ would not be called Teacher. Yet we must believe in Him and hear His voice by faith for Him to be our Teacher! That is fundamental to Christianity.
Now some would consider me a Protestant Christian, yet many Protestant Christians might refer to me as a Charismatic Christian. I am fine with all that. And I meet Protestants Christians and Charismatic Christian, (if you want to separate them) that think Catholics are something completely different altogether, as if they are not Christian. I also have meet Catholics who thing Protestant Christians are something completely different altogether, as if they are not Christian.
So what do you think I do? --- I talk to my Lord and Teacher, Jesus Christ, about this - and I am telling you that He tells me that is wrong. He not only tells me that thinking is wrong but has given me tons of examples. So who then is saying those things to me except those not listening to Him?
In Christianity, different Christian churches have lots of different traditions!! That does not mean they are incorrect, it only means they have different traditions. I have mine. I pretty much make it a tradition to get up in the morning, sit in my favorite chair and pray the Lord's prayer with some things added, like praying for our leaders. Then I set my mind and heart on hearing what the Lord has to say to me personally.
Yet if someone else seeks Him before going to bed instead of in the morning, of what concern is that to me? Perhaps they want to light a candle and seek Him? So what. Perhaps they like a handful of beads? Ok - whatever helps them seek our Lord Jesus Christ and listen to Him is a good thing, isn't it?
So the problem comes when they are making it about traditions and such yet their heart is far from Him. And that problem might be more a personal problem than a denominational problem. Of maybe it could be a general problem in a group of people, but still not apply to all of them.
Isaiah was an off-spring of Abraham, right? He knew the Lord personally, right? Yet he wrote to God's people about hearing from the Lord and not having their heart far from Him. It is recorded in the Scriptures which God has us studying, right, so it still applies, right?
Is 29:1 Woe, O Ariel, Ariel the city where David once camped! Ad year to year, observe your feasts on schedule. I will bring distress to Ariel...
Is 29:13... Because this peole draw near with their words and honor Me with their lip service, but they have removed their hearts far from Me
That is the problem many have, and perhaps most, like in the time of Isaiah. They have made it about traditions and give lip service to Jesus Christ, but they don't listen to Him. They have removed their heart far from Him.
Is 30:9 For this is a rebellious people, false sons, Sons who refuse to listen to the instruction of the Lord
So who is thinking that the church and not the Lord is the fundamental part of Christianity, except for the person who is not listening to the Lord for instructions?
I don't care if a person is Catholic or Protestant. I don't care if a person is Charismatic or very Conservative. I care that a person listens to the Lord! I don't care what traditions they have, but I do care that they listen to Him!! Otherwise they are a false son! So I do care that they understand that Jesus Christ is the fundamental thing in Christianity. He said His sheep hear His voice. He said His words are spirit and are life. So you had better know Him personally, and saying I know Him through the Bible is not knowing Him at all! He has a voice and speaks words. Isaiah start of His writing by explaining that.
Is 1:2 Listen, O heavens, and hear O earth; For the Lord speaks...
You had better keep that commandment
Deut 6:3 O Isreal, you should listen and becareful to do it.
Deut 6:4 Hear, O Israel! The Lord is our God, the Lord is one!
Deut 6:6 These words, which I am commanding you today, shall be on your heart
Are they? Are the words "Hear, O Isreal, and hear O earth" on your heart like commanded? Do His people actually take the time to listen to Him? Or is it just lip service? Who then says their church and not their Lord has the answers for them, expect the person not listening to the Lord their God?
The fundamental thing in Christianity is of course listening to Jesus Christ via the Holy Spirit! If you don't then alsorts of silly ideas come into your head.