I'm sorry ding, but that is simply untrue and unbiblical. You have said that before and I am pretty sure I responded to that statement before, but I'll do it again because I don't want people to be misled. God doesn't want us to be unsure of our eternal fate. Why? For numerous reasons, starting with lack of assurance leading to worry, stressing and striving through our own efforts, which btw shows a misunderstanding of the entire Gospel.
There are a number of verses I could share on assurance of salvation, but here are just a couple. Note the bolded text:
He who has the Son has the life; he who does not have the Son of God does not have the life. These things I have written to you who believe in the name of the Son of God, so that you may know that you have eternal life.
1 John 5:12-13
The Spirit Himself testifies with our spirit that we are children of God.
Romans 8:16
I think the problem in regard to Catholics with that idea (that no one knows their fate) is that it comes from an incorrect teaching or a lack of teaching on salvation. And this is very, very, very important.
Despite what the Catholic church teaches or doesn't teach, Jesus made it very clear that
you must be born again. No one who is unregenerate (still in their flesh, their natural state) will see the kingdom of God. And here's the thing… when you are born again, you know it. There is no doubt or question about one's salvation when you are truly saved.
Please don't let your loyalty to a particular church become more important than what is actually true because salvation is very important. If someone is not sure of their salvation, then it sounds like they don't understand the Gospel. We are not saved through getting sprinkled with a little bit of water as a baby, or going through religious sacraments. You must be born again. Jesus made that very clear, read John 3.
That means not putting faith in your own works or in religion but getting truly reconciled to God. First there must be an understanding of one's true spiritual condition (a sinner in need of forgiveness) repentance which means changing direction, in other words deciding to turn away from evil and toward good, then receiving the gift of salvation by simply believing and trusting that JESUS paid the price for you. It involves a complete surrender to God, not a half-hearted religious thing, but a genuine change of mind/heart. We are saved by God's grace, through faith. And when we get saved we become a new creation, literally, and life will never be the same. Again, I'm bringing this up because you said we don't know our eternal fate, but that is not true, when you are a child of God, born from above, you know!