Prove it.
Easy. The Church is to be one, not many. It is in Scripture:
And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it. Mat 6:18
Here Christ says his Church will not be destroyed.
I have yet many things to say unto you, but ye cannot bear them now. Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come. John 16:12-13
But if I tarry long, that thou mayest know how thou oughtest to behave thyself in the house of God, which is the church of the living God, the pillar and foundation of the truth. 1Tim 3:15
Here Christ says, and Paul reaffirms, that the Church will always teach the TRUTH.
Then Jesus came to them and said, "All authority in heaven and on earth has been given to me. Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age."Mat 28:18-20
Again, here Jesus assures us that He is always with us, to the very end.
So Christ says His Church will not be destroyed or fall away from him, that the Holy Spirit will guide the Church to always teach the Truth, and He will always be with us.
All in the clear words of Scripture.
The Church is much more than a collection of nice people who read a Bible and believe anything they want.
The Catholc Church. Est. 33 A.D.
What other Church can make this claim????