I was sipping some coffee on a break with a friend from work. We were discussing religion and how people convert from one faith to another (this particular conversation being Christians who convert to Islam). The conversation obviously migrated into religious extremism and thoughts of how the Pope deals with such topics from where he sits. My friend made the quip, "If you ever get too disappointed in the Pope, you will probably just pack up and go back to Protestantism". I followed up with "No... if I leave Catholicism I will have left the Christian faith completely".
The shock in my friend's face was amusing, yet intriguing. This is a truth that has been normalized to me. Yet, some people I meet, even Catholics may be surprised by that (which no Catholic should ever be surprised by such a statement). Being a former Protestant, and now a Catholic, it is clear to me that Christ established one Church. Jesus didn't lie to his Father in Heaven when he prayed his Church be one. He wouldn't have prayed such a thing had he known that it would not be the case- He's God.
This is not to say that any other form of Christianity does not have some good elements or some semblance of truth, but that it is not the source of Christ's one Church. If I were to pack up and leave my home in a metropolis, I am not going to settle in the outskirts to look from afar. Being a former Protestant, I know that the faith of the Church of Christ is not up to me, it is up to Christ himself. If Christ gave that authority to His Church, it would be spelled out his way. So if I were to leave that, it would be because Jesus Christ is not who he said he was. It would be that God is somewhere else, and that is where I have to go.