You have received very good references. I donât know which protestant denomination you belong to, but being a Christian I can quote the scripture to you. John 10:16 Jesus said " I have other sheep not of this fold, and these I must lead, and they will hear my voice, and there will be one flock, one shepherd" The Catholic church makes the claim that she is One, Holy and Apostolic. Heresies have caused divisions and splits in the Church (and are the work of Satan) which formed other churches. There are similarities, and and there major differences. Since Vatican 11, the Catholic church stressed ecumenism, promoting a coming together to reach a better understanding of different faiths, and to agree where we can, and to disagree where we must, in the spirit of Christian love. This will help to bring about the desire of Christ, to makes us one. We do share the Sacrament of Baptism, so we are united to that degree, which is essential. But we are not united in some profound means of grace, eg. the true interpretation of the Eucharist (our Communion) which we believe is the actual body and blood of Jesus Christ (a Divine Mystery of Faith). There is also different belief on the sacrament of Reconciliation (confession). There exists the personal interpretation of Scripture, and no recognition of the appointment of Jesus,about the teaching authority of the Church or his words about the Pope, and the power to forgive, given by Jesus. So you ask are you missing something, we know that you are. You may feel comfortable where you are because you are not aware of some of these major differences. I can assure you if you seek to know, and become more informed you may be very surprised. I received this reaction from a person from another christian faith I just sponsored who just became a Catholic, and now from her companion.