You are assuming that the ‘true church’ must be one and only one denomination. Why should I make this assumption?
But even if I were to make this assumption you can not prove from Scripture and history that you are the one true church.
The thing that people don’t know and/or understand is this: If it weren’t for the Catholic Church, they wouldn’t even HAVE a Bible!
They don’t look deeply into the history of the early church, and these people want the glory, instead of giving it to God.
If they are “good preachers” they think they are speaking the truth. But the “worship service” is centered on the PREACHER.
Most people don’t understand different “denominations” because they don’t know where they originated.
They were all started by someone who disagreed with the Catholic Church, and splintered off into some new dogma.
And then splintered again and again, until there are 35,000 different “denominations”.
People disagree, it is in our nature. They denounce our faith because they don’t know enough about it.
Martin Luther was a Catholic monk trying to “reform” what he saw as evil. He didn’t reform anything, he started a new church, he broke the Apostolic succession.
Henry VIII broke off because the Pope wouldn’t grant him a divorce. He wanted a divorce because he mistakenly thought the wife was responsible for bearing a son or daughter. (We now know the male is the contributor of the Y Gene which will give forth a son to be heir to the throne.)
But the Anglican Church continues, based on this mistaken belief!
Calvin and Knox were politicians who were involved in getting rid of Queen Mary, not really any dogma there, other than predestination.
From there, we have Puritans, who wanted to strip the church of art and beauty.
Numerous churches were formed in the US based on the belief that they were living in the End-Times during the nineteenth Century-- Millerism, Church of the Brethren, Mormonism, and several others. These churches were very anti-Catholic, and believed that the Pope would be moving the Vatican to some place in Missouri and “Taking over” this country.
They border on the bizarre.
They all have one thing in common, and that is Jesus Christ, though a distorted view and relationship with Christ, since the Eucharist was lost along the way.
My hope is that we can pray enough for them to come back into the fold. They don’t know what they are missing.
They get hung up on our ‘rituals’ but they still have weddings, funerals, and so forth.
They are in Spiritual Freefall. They deserve the truth and the life, and they deserve our prayers.