In John 17, Jesus prays one of His longest prayers—that for the unity of the Church to be identical to the unity between the Father and the Son. It also seems to be the one the Father has most likely (as far as appearances go) answered with a resounding “No.”
Skeptics have for centuries cited various divisions, sects, and denominations within Christendom as evidence against its veracity. I’ve always felt that these ‘divisions’ were like the various organs of a body, in accord with Paul’s descriptions of the Church being one Body with different parts, but unified in purpose…just seemingly suffering from some sort of auto-immune disease caused by human nature and the actions of the Adversary.