1. What if one sins, and the immediately dies before repenting?
2. Even the scripture you quoted cannot be applied exactly as you are applying it because it says, "that has not lifted itself up" (PAST TENSE) ...everyone has at sometime in the past lifted up their soul in sin against God...and so should be disqualified from heaven...but Christ cancels the record of sin against us with its legal demands...!
If we are to be ready for when Jesus comes, why should we not be ready if we die and are in sin?
Mark 13:36 If he comes suddenly, do not let him find you sleeping.
Luke 21:34 "Be careful, or your hearts will be weighed down with dissipation, drunkenness and the anxieties of life, and that day will close on you unexpectedly like a trap.
Matthew 24:42 "Therefore keep watch, because you do not know on what day your Lord will come.
Matthew 24:44 So you also must be ready, because the Son of Man will come at an hour when you do not expect him.
Matthew 25:10 "But while they were on their way to buy the oil, the bridegroom arrived. The virgins who were ready went in with him to the wedding banquet. And the door was shut.
Matthew 25:13 "Therefore keep watch, because you do not know the day or the hour.
Mark 13:35 "Therefore keep watch because you do not know when the owner of the house will come back--whether in the evening, or at midnight, or when the rooster crows, or at dawn.
Luke 12:38 It will be good for those servants whose master finds them ready, even if he comes in the second or third watch of the night.
Luke 21:36 Be always on the watch, and pray that you may be able to escape all that is about to happen, and that you may be able to stand before the Son of Man."
Revelation 3:3 Remember, therefore, what you have received and heard; obey it, and repent. But if you do not wake up, I will come like a thief, and you will not know at what time I will come to you.
Revelation 16:15 "Behold, I come like a thief! Blessed is he who stays awake and keeps his clothes with him, so that he may not go naked and be shamefully exposed."