Every Protestant denomination is a cell of the Church, even if it came from another cell and that cell came from some other cell, and so on and so forth, to the Reformation. Every domination, therefore, has as its founder a man, not the God-Man, Who had founded the Church. Some believe Jesus founded te denomination through their founder, but this belief has no basis in Scripture, wherein God’s Word clearly states He Himself will build His Church. So Jesus is the Founder of the Church, and man is the founder of every other church and denomination. God founded His Church, and men, thinking themselves His Equal, founded theirs. Only God could found the Church, too, because only God could die on the Cross and establish a new Covenant between Himself and His creatures; no man could ever do this, so to found a new people of God is to attempt to take the Lord’s Throne. To reiterate, Christ founded the Church, and waywards founded every other one.
The other major difference is that the Church has not changed, while every denomination and church has since its founding. This is not significent until you remember Scriptures: The Church is Christ’s Body. Those who disbelief the Eucharist, disbelieve also these words, calling them metaphorical, just as they call the Eucharist a symbol, but those who have studed the Scriptures know otherwise. The Church is His Body, and Christ is God and Man. God cannot change. So the Church cannot change in faith, worship, or communion, though she can lose some members to Hell and adopt new displines and traditions to better serve God and man. The Church preserves, though some of her members are lost and she sometimes gets new ornaments and clothing to please her Spouse. But every other church and denomination has changed over the years, whether its the Calvinists - who no longer believe Jesus is St. Michael - or the Sola Scripturists - who now have their own form of sacred tradition - or any other group of Christian pilgrims.