Yes, you can loose your salvation (enterance into heaven) if you die with unrepentant mortal sin on your soul.
And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand.My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father's hand.
I and my Father are one.
Then the Jews took up stones again to stone him.
So, aren't you also 'no man', so that once Justified 'no man' including you, can pluck you from God's hand? I think 'no man is very very very very inclusive, even of you. Justification is different from sanctification. A saved sinner is likely to have sins unconfessed when they die. It would be a shame if you were justified by His blood and it was enough to cleanse you from all unrighteousness. How many of your sins were in the future when Jesus was on the Cross?
Your premise does not conform with what Scripture teaches us. According to Paul...
Romans 7: ... 11 For sin, seizing the opportunity afforded by the commandment, deceived me, and through the commandment put me to death. 12 So then, the law is holy, and the commandment is holy, righteous and good.
13 Did that which is good, then, become death to me? By no means! Nevertheless, in order that sin might be recognized as sin, it used what is good to bring about my death, so that through the commandment sin might become utterly sinful.
14 We know that the law is spiritual; but I am unspiritual, sold as a slave to sin. 15 I do not understand what I do. For what I want to do I do not do, but what I hate I do. 16 And if I do what I do not want to do, I agree that the law is good. 17 As it is, it is no longer I myself who do it, but it is sin living in me. 18 For I know that good itself does not dwell in me, that is, in my sinful nature. For I have the desire to do what is good, but I cannot carry it out. 19 For I do not do the good I want to do, but the evil I do not want to do—this I keep on doing. 20 Now if I do what I do not want to do, it is no longer I who do it, but it is sin living in me that does it.
21 So I find this law at work: Although I want to do good, evil is right there with me. 22 For in my inner being I delight in God’s law; 23 but I see another law at work in me, waging war against the law of my mind and making me a prisoner of the law of sin at work within me. 24 What a wretched man I am! Who will rescue me from this body that is subject to death? 25 Thanks be to God, who delivers me through Jesus Christ our Lord!
So then, I myself in my mind am a slave to God’s law, but in my sinful nature a slave to the law of sin.
Sorry, there are no degrees of sin. Some sins might have greater consequences, but every sin you commit, and we all commit a ton of them, is a mortal sin. I invite you to have a nice forever. I intend to. 😇😱
A Catholic fabrication.
If the Christian dies with *mortal* sin on their soul, they will have to answer for it, but it does NOT cost them heaven.
That is a works based salvation.
Don't forget that Jesus taught that the sin of the heart is the same as acting on it. To lust after a woman is to commit adultery with her and to hate a person is to murder them in your heart.
There's not a person alive who does not have mortal sin on their soul because there's not a person alive who does not sin in their thoughts.
It's not merely the actions.
The Pharisees were perfect according to keeping the letter of the law and as lost as all get out.
Putting confidence in the flesh gets one no where.
Please show this in the Word.
To be clear.....you're a good catholic....you're driving down the road and somebody swerves in front of you. You fly into a bit of road rage hating the idiot in front of you. He brakes hard and you rear end him sustaining fatal injuries.
As you've committed a mortal sin in your road rage and it's unconfessed.....Heaven or Hell?