Forgotten Truth: Is Catholicism Christian?

In light of some current events within our nation, with the visit of the "pope," I wanted to share some quick thoughts.
EDIT 2/4/2019: Continued current events in multiple forms have brought this to mind again, and additional information has been added.

Much ado was made about the papal visit and all of the things that he would be doing that had been done by no previous pope. Many talked about how nice a man he is and how wonderful some of the things he said are.
There is good reason why his predecessors had so little to do with this nation, and it is unfortunate that most seem to have forgotten that reasoning. This nation was largely established by those fleeing religious oppression, and one of the major founding ideas of our nation was religious liberty. Our forefathers remembered well the religious oppression that Catholicism maintained for centuries, and the state sponsored churches that followed in that tradition established by the Catholics.
The US maintained a strong distance from Catholicism at many points because of that background and because of the religious convictions of the people that lived here.

I could make a number of points from scripture, and I could say a lot more, but let's do it the easy way.

Here are a few quotes from the founders of most of the Christian groups within the US (or notable preachers from said groups) on what they thought of Catholicism and the pope.

Martin Luther (Lutherans and considered one of the great Reformers)

"We here are of the conviction that the papacy is the seat of the true and real Antichrist…personally I declare that I owe the Pope no other obedience than that to Antichrist" (sermon on Aug 18, 1520).
“Already I feel greater liberty in my heart; for at last I know that the pope is antichrist, and that his throne is that of Satan himself” (after a Papal edict against him).
"I am practically cornered, and can hardly doubt any more, that the Pope is really the Antichrist... because everything so exactly corresponds to the way of his life, actions, words and commandments" (Schriften volume 21a, column 234).

John Calvin (Presbyterians and others)

"Daniel and Paul had predicted that Antichrist would sit in the temple of God...we affirm him to be the Pope…Some persons think us too severe and censorious when we call the Roman pontiff Antichrist. But those who are of this opinion do not consider that they bring the same charge of presumption against Paul himself, after whom we speak" (Prophetic Faith of our Fathers Volume 2).
"I shall briefly show that (Paul's words in II Thess. 2) are not capable of any other interpretation than that which applies them to the Papacy" (Institutes).

John Wesley (Methodists) - Antichrist and His Ten Kingdoms

He is in an emphatical sense, the Man of Sin, as he increases all manner of sin above measure. And he is, too, properly styled the Son of Perdition, as he has caused the death of numberless multitudes, both of his opposers and followers.

Westminster Confession of Faith - 1646 (Presbyterian) - Chapter 26, Point 4

There is no other head of the Church but the Lord Jesus Christ: nor can the Pope of Rome in any sense be head thereof; but is that Antichrist, that man of sin and son of perdition, that exalteth himself in the Church against Christ, and all that is called God.

For those of you who consult your WCFs today (like I do from my handy "Trinity Hymnal" which is a Presbyterian hymnal, and has the WCF in the back), you won't find most of that statement. American revisions of the WCF and the adaptation of it by the PC USA in 1903 removed the statement that the Pope is the Antichrist.


London Confession of Faith - 1689 (Baptist) - Chapter 26, Point 4

The Lord Jesus Christ is the Head of the church, in whom, by the appointment of the Father, all power for the calling, institution, order or government of the church, is invested in a supreme and sovereign manner; neither can the Pope of Rome in any sense be head thereof, but is that antichrist, that man of sin, and son of perdition, that exalteth himself in the church against Christ, and all that is called God; whom the Lord shall destroy with the brightness of his coming.
(Colossians 1:18; Matthew 28:18-20; Ephesians 4:11, 12; 2 Thessalonians 2:2-9)

I find this particular one fun for a couple of reasons. Yes, I am a Baptist. However, I like the more positive outcome at the end that was added, recognizing the inevitable destruction of Catholicism by the return of Christ. Also, I love the way that the Baptist confession adds in references to each point.

Charles Spurgeon (Baptist)

"We must have no truce, no treaty with Rome. War! war to the knife with her! Peace there cannot be. She cannot have peace with us—we cannot have peace with her. She hates the true Church, and we can only say that the hatred is reciprocated. We would not lay a hand upon her priests; we would not touch a hair of their heads. Let them be free; but their doctrine we would destroy from the face of the earth as the doctrine of devils. So let it perish, O God, and let that evil thing become as the fat of lambs. Into smoke let it consume: yea into smoke let it consume away."
- Excerpt from sermon (May 1, 1859)

Quite simply, both the religious leaders of the US and the common person has largely forgotten truths that were nigh-universally agreed on in the past. The papacy is not only Christianity in error, but the great enemy of Christianity. 

A great example in this particular case is Ian Paisley. While I disagree with him on many issues, he made the point more than adequately when he was a member of the European Parliament.
Perhaps it is the peaceful and cushy existence that we have experienced in America. We don't face persecution for our faiths. However, in Paisley's Northern Ireland, there was still that battle of Catholic against Non-Catholic, so that he was unable to merely push aside the historic view for more politically correct ideas.
So, let's let the deceased Mr. Paisley speak for himself.