It is a huge jump to start believing in God. Then after that, it is another huge jump to believe He has a Son, and yet there is still only one God.
So, all Christians have this basic part of Faith agreed upon. The major differences between Catholics and protestants are usually as follows (keep in mind these are GENERAL protestant beliefs, I can’t speak for every single one):
Authority: Protestants believe our only infallible authority is the Bible, whereas Catholics believe also in the infallability of the Pope and the Magisterium.
Salvation: Protestants believe we are saved by Faith alone, while Catholics believe works play an important process as well. However, in my various conversations with protestants, it usually becomes apparent that Catholic and protestant viewpoints on this subject are not TOO different. But definitely far enough apart to create a discrepancy.
Mary and the Saints: Catholics honor, venerate and pray to Mary and the Saints. Protestants don’t.
Purgatory: Catholics believe in purgatory. Protestants don’t.
Sacraments: With the exception of a few Protestant groups, none believe in any sort of Sacraments. Some believe in Baptismal regeneration (though not very many, seemingly), and a few believe in consubstantiation (most notably Lutherans), although even there, they don’t believe in transubstantiation. Catholics believe that Baptism, Penance, the Eucharist, Confirmation, Marriage, Holy Orders, and Anointing of the Sick are all Sacraments given to us by God to infuse Grace. The most important of these Sacraments, however, is the Eucharist, the centerpiece of Catholic theology. Because as Jesus said, “Unless you eat my flesh, and drink my blood, you have no life in you”.
So there are diffferences, and, at least in my opinion, the Catholics are always right. Protestantism broke [i:2iy2a78c]away[/i:2iy2a78c], and I believe that was and still is a grave error. The Catholic Church claims to be the One, Holy, Catholic, Apostolic church, and it also claims no other churches possess these qualities. So basically, if one isn’t in the Catholic Church, one is saying one doesn’t believe what it teaches, because THAT is what it teaches.
But you are definitely correct in saying that the differences are not as pronounced as some suggest. Also, I hope eventually all schismatic and heretical churches eventually re-join their mother, the Catholic Church. That would TRULY make the devil quite unhappy indeed.