I have tried explaining this to my wife's uncle several times. He's a great guy. A good family man. He's generous and compassionate. However, he goes to Mass every day and is constantly praying the rosary. He is terrified of the idea that he might do something to keep him from being saved.
I've shared The Gospel with him and explained how once your saved nothing can pull you out of Jesus's hand. It's sad that he doesn't have the eyes or ears to see or hear the truth.
Sad...I had an aunt like that...Beyond my human comprehension...Seems a spiritual influence...