First of all, if you were a Catholic and you weren't reading the Bible - shame on YOU, not the Church.
REAL Catholics read the Scriptures.
As for "knowing" where you'll go when you die - you may have a moral certitude, IF you remain faithful to the end. Otherwise - you don't.
The Bible assures us that salvation is a process - not a one-time, slam dunk event.
Aas Christians are ALREADY SAVED (Rom. 5:1, 8:24, Eph. 2:5–8).
This is Initial Salvation – God give us the initial grace to believe.
However, because Salvation is a LIFELONG process – it ALSO says that I am BEING SAVED (1 Cor. 1:8, 2 Cor. 2:15, 7:1, Phil. 2:12, Heb 12:14).
This is Ongoing Sanctification – God is sanctifying us throughout our life as we cooperate with his grace.
Because of this, I have the hope that I WILL BE SAVED (Matt. 24:13, Rom. 5:9–10, 1 Cor. 3:12–15).
This is Final Sanctification/Salvation – We die and go to heaven having endured to the end.
You don't get there without cooperating with God's grace . . .