There was a time when the church aimed to be universal. Such was clearly the apostolic goal. But heresies crept in.
Act 20:30 "Even from your own number [narcissists] will arise and distort the truth in order to draw away disciples after them." Separately from diluting the gospel with heresies is the idea that God himself is a monster partial to a secret elect (such seems to have been credited by Gnostics), such that the love of God for sinners is in reality a fiction. [From a recent Tribunal panel judge (whose very comments led to the hearing being abandoned) "Responding to a comment that only atheists should be in public office, Mr Purkis posted: 'Damn right, you won't catch us killing in the name of our non-god.' "]
So I would contend that if not all men are saved, it is only because
man has determined that it should be so, not Christ. Woe to the man through whom such things come (said Christ).