I am sure that you are right that there have been several Protestant pastors who have fallen away permanently. That relates to one of my strongest memories as a counselor at a Billy Graham crusade. During his invitation, he specifically invited pastors who were not right with God. At the time I was amazed at the presumption, but he was obviously right. Non believers hold absolutely every station in life, including that of the clergy of all faiths.
I also agree that we can't know the exact paths of our lives to come. All we can do is know and be firm in who we believe, and take rest and comfort in knowing that He will keep His promises to us. While the math might say I could be a false believer, I don't worry about it. If what is actually in my heart turns out, in FACT, to be false, then I deserve what I get. By my own beliefs there is nothing I can do about it. :)
Well, I think we agree more than I had thought previously. In the past, I had thought that your bible verse quotes and other remarks had made it clear that you do not believe you could POSSIBLY EVER fall, that God already has you marked as part of the flock and would ABSOLUTELY prevent you from falling away. The above paragraph is much more in tune with Scriptures and common sense.
Catholics believe the same thing, for the most part. We do not have absolute certitude that we will persevere until the end. If you read some of the lives of the saints, you will find they have a particular humility on this very subject. While we do not have absolute certitude, we have a moral certitude that God is righteous and will guide us through until the end, that God will place within us the desire to remain on the narrow road and will reward us with the promised inheritance at the end...
Regards