"Beloved, do not believe every spirit, but test the spirits, whether they are of God; because many false prophets have gone out into the world." 1 John 4:1
In this present age, it seems that there is a lot of confusion, or ignorance on the subject, that Christianity and Catholicism are at the very least compatible. I believe that this is greatly contributing to the deception making it's way through the Church, allowing false doctrines and teachings to creep in, and paving the way for Christians to be accepting of a one world religion.
Biblical Christianity and Roman Catholicism are anything but compatible, indeed, I would go so far as to argue that Catholicism is a false religion. It truly frightens me to see Christians embrace either the religion itself, or aspects of it, some going so far as to welcome some of the beliefs and/or symbols of the Catholic church into their own churches - which is another subject for another day. The article Roman Catholicism Compared to Biblical Christianity does a good job of clearly laying out and enumerating many of the doctrinal differences. It is important to fully understand what these doctrinal beliefs are, in order to be able to discern how much they truly differ from the teachings of Scripture. Here are a few examples of Catholic doctrine that are defined and explained in the article....
Preface: We Catholics maintain that the Bible is not the
sole source of Christ’s teaching, but that we have a double rule of
faith, namely, Bible and Tradition. Tradition is the sum of revealed
doctrine which has not been put down in Sacred Scripture
but has been handed down through legitimate pastors of the Church from
age to age.
Expiation (*atonement): The work of expiation continues through the unbloody
sacrifice of the Mass for all time. Hence, for us (Catholics),
the greatest work of expiation is through the sacrifice of the Mass
by which God is placated.
Grace: Grace is lost through mortal sin; it is preserved and
increased through prayer and works done under the influence of
God, and by means of the sacraments duly received.
Infallibility: The belief that the pope and bishops are said
to be incapable of error when proclaiming definite doctrines
involving faith and morals.
...and there are more. These few statements alone should make any Christian cringe. We know that Scripture alone is the infallible Word of God, and that there is nothing that man could add to it, with the Lord clearly warning us not to add to His Word (2 Timothy 3:16, Proverbs 30:5,6). We know that Jesus Christ alone paid the atonement for our sins by dying, once for all (Hebrews 10:10-11, 1 John 2:2). We know that grace is the free gift of God and that there are no amount of words or good deeds in the world that could earn us the favor of the Lord (Ephesians 2:8-9). The doctrines that the Catholic church practices are not "minor" differences such as worship style preferences. They are pretty scary things to say; they are heretical.
"Beware lest anyone cheat
you through philosophy and empty deceit, according to the tradition of
men, according to the basic principles of the world, and not according
to Christ. For in Him dwells all the fullness of the Godhead bodily; and you are complete in Him, who is the head of all principality and power." Colossians 2:8-10
In regards to how the Catholic church is playing a role in bringing about a one world religion, it is clear to see that Pope Francis is hugely encouraging an ecumenical movement. He seems to be focusing on Islam, though not exclusively by any means. This further ecumenical pollution of already muddied waters is alarming to me as I see Christians being slowly desensitized to the religion and the ecumenical movement. I hope you will join me in praying for eyes to be opened to Truth, and warn others of this false religion before it further impacts Christ's church.
*I added this word for clarification