The reason I’m not Roman Catholic is really quite simple (although if you want the proof of my reason, it will require some homework on your part): There’s just no way to reconcile Roman Catholic doctrine with Scripture.
You see, Roman Catholicism teaches certain unscriptural things such as never-ending punishment, the immortality of the soul, salvation based on a “free will” choice, that there’s only one Gospel, and that Jesus only started one church, along with many other doctrines which blatantly contradict the Bible. However, if one considers the context of Scripture as a whole, the only possible conclusions one can come to are that there are multiple Gospels and multiple different types of salvation referred to in the Bible, that everyone will experience at least one of these types of salvation by the end of the ages, that the dead known nothing because they’re unconscious (and this included Jesus Christ while He was dead too), and that the type of salvation Paul taught the nations about is not based on any choices we make at all (in fact, “free will” is a logical and scientific impossibility anyway), among various other scriptural truths which contradict Roman Catholic doctrine. The bottom line is that there’s no way for someone who is being honest with the text to conclude otherwise, and if the Bible is indeed the inerrant word of God, then it simply makes it impossible for Roman Catholicism to be true.
Now, I know that Roman Catholics will claim that I’m misinterpreting the relevant passages (and that even most Protestant Christians will disagree with many of the assertions I made there too), but there’s simply no way to interpret Scripture as a whole in any other way without ignoring the clear meaning of the words in the text. And while I don’t have the time to get into the details which prove these assertions here in this post, I don’t have to, because I already did so a number of years ago in this (long) Bible study: What the Bible really says about heaven, hell, judgement, death, evil, sin, and salvation
If you take the time to read that whole study carefully from beginning to end, I can guarantee that you’ll be forced to agree with the above assertions (presuming you believe that Scripture is indeed the inerrant word of God, of course). That might sound presumptuous of me, but so far, of the thousands of people I’ve shared that study with over the years since I wrote it, literally every single person who has gotten back to me telling me they’ve read the whole thing has also told me that they now agree with those assertions themselves too. So if you’re curious why I believe that Roman Catholicism can’t possibly be true (and why I believe most of the doctrines that even most Protestants hold to are equally incorrect), after reading that study, you’ll understand why completely. But if you do read it all and still disagree, I’d love to hear your answers to the questions I ask throughout the study.