Despite the importance the early churches put on the Eucharist (communion) meal, I stand by the following argument, which I sent in answer to an email question about which church the gates of Hades will not prevail against:
I think “church” has nothing to do with organizations. I believe it is the family of God. I wrote an article on the purpose of church at https://www.rebuildingthefoundations.org/find-a-church.html. I think Jesus was saying that if we come together, speak the truth in love to one another, get to know one another, and provoke one another to love and good works, then the gates of Hades won’t stand a chance against us (Heb. 10:24-25; Eph. 4:11-16). If anyone reads a history of the Roman Catholic Church from 900 to about 1430, and still thinks it is remotely possible that the Roman Catholic Church was the one true church carrying the authority of Jesus and Peter, then I would consider that person irrational.
It is true that most Protestant churches are not living out Hebrews 10:24-25; Ephesians 4:11-16; 1 Corinthians 12:12; etc. My encouragement to everyone is to find people you can live those things out with, even if just a few. It does not matter what branch of Christianity they are from. I would say that the Lord’s Supper is really important, but not as important as the passages I just mentioned. One day you will be judged, standing alone, not as a church, by your works. Thus, I encourage you to surrender to Jesus, be filled with the Holy Spirit, and get the empowering fellowship the Bible talks about. “Pursue faith, love, peace, and righteousness along with those who call on the Lord out of a pure heart” (2 Tim. 2:22). In today’s messed-up age, you will have to find individuals to do that with, whether you are Protestant, Orthodox, or Catholic.
May God grant you understanding of these things and a concern for the day when Jesus will tell you whether you fed him when he was hungry or whether you did not and reward you with eternal life or everlasting fire (Matt. 25:31-46). As far as I can tell, on that day, no one at all will care whether you were Protestant, Catholic, or Orthodox. Instead, we will all care whether we practiced true and undefiled religion by helping widows and orphans and remaining unspotted by the world (Jam. 1:26-27).
There are a lot of opinions and rumors about Constantine, the Council of Nicea, and the events of the fourth century that changed Christianity to Christendom. Not only will you get the incredible story, with all its twists, plots, and intrigues, but you will find out how history is done and never wonder what is true again.