Not they are not all Israel who are of Israel. This is true for all people of Israel, those graphed in or not.
The only issue that decides this question, is do you truely have Him, His presence in your heart? I’ve known/meet peoples from every denomination who don’t and I’ve meet Evangelicals, Mormons and Catholics who do.
He _is_ the _only_ one who knows; He decides, cause he experiences it too; it is a partnership. He measures a man/woman by their heart. A right heart produces fruit and good works without a right heart are a clanging gong.
The only issue that decides this question, is do you truely have Him, His presence in your heart?
- - - - -
Interesting you list Mormons you know that do, since this is NOT Mormon belief or teaching. They may say something similar or dance around it, but they openly reject a personal relationship with Jesus Christ.
Mormon Apostle gave a talk at BYU on this very subject:http://speeches.byu.edu/reader/reader.php?id=6843
Also, can you have Jesus in your heart when you believe in a false Jesus, one that is not eternal, not always God, elder brother of Satan, etc.
So, while I do believe Catholics can, Mormons cannot. If they did then they would leave Mormonism in a shot. I’ve seen it over and over again. If you have a relationship with Christ, you cannot stay in Mormonism very long at all, much less believe any of it.